What Kills Us?

  • E-Mail this Article
  • View Printable Article
  • Text size:

    • A
    • A
    • A

We are all, I suppose, victims of our own obsessions and one of mine is the notion that among the many things we don't teach well in aviation is risk assessment. That's not risk management, mind you, which I view as an overused buzz word, but rather a realistic grasp of what's most likely to kill us when flying an airplane. That's another way of saying that many—if not most—pilots worry too much about the wrong things and not enough about the real killer risks.

I notice this when flying with other pilots or speaking to owners about equipment upgrades. Specifically, some pilots are absolutely terrified of midair collisions. While that's understandable, it's not necessarily justifiable. The graphic at right shows why. This is data I distilled from all of the general aviation fatal accidents in 2010. The numbers to the right of the circles represent the actual accident rate per 100,000 flight hours that these categories represent while the circles themselves graphically represent the relative size of the risk.

These categories were my own and intentionally painted with a broad brush so the risks would stand in sharper relief. There's definite bias in my analysis and I'll get to that in a moment. Also, there's obvious anomalous exposure inconsistency. On every flight, you're exposed to stalls, to loss of control, to running out of fuel and into trees and rocks. But icing and convective events represent a smaller universe because not as many pilots venture into such challenging conditions.

From my perspective, what the graphic shows is that pilots tend to have an inverted understanding of risk and what's most likely to kill them. So they spend big dollars on traffic systems to mitigate what's practically the smallest overall risk: a midair. There are thousands of traffic systems out there and although they're good, between-the-ears comfort providers, I doubt if they've moved the overall accident needle in the slightest. Midairs as a percentage of total accidents haven't changed much in the 20 years I've been following these numbers. Why? Big sky theory works. Big sky and not that many airplanes. See and avoid fills in the small gaps.

Sadly, upper strata of the accident heap hasn't changed much, either. Stall-related accidents are at or near the top of the accident results/causes year after year. I'm using the term results/causes deliberately because of the often inseparable juxtaposition of the two. If an engine fails and the pilot stalls the airplane trying to perform an emergency landing, what was the cause? The engine failure or the stall? Was the engine the cause, the stall the result? If we assume any pilot should be able to land an airplane survivably after an engine failure, then the stall looms larger as the fault in the system, even though an engine failure or fuel exhaustion may be been the gateway event for the stall. That's where the bias comes in. You might code these accidents a little differently than I would.

Not that it makes much difference, frankly. In that group of stall accidents are a couple that involved engine failure or fuel exhaustion, but the majority are accidents in which a pilot—while landing or taking off—simply stalled a perfectly functioning airplane. As much as I am at a loss to explain why this happens so often, I am equally baffled by how pilots can be so utterly unaware of the stall risk. It seems obvious that our stall awareness training isn't entirely broken because it effectively reaches the vast majority of pilots who can fly an airplane without stalling it. But for an unlucky slice of the pilot population, aerodynamic stalls, as a concept, seems to elude. Technology may or may not help. Cirrus invested heavily in a spin-resistant wing design, yet stalls and spins are a significant feature of the Cirrus accident record. If owners had a real sense of the stall risk, would they be more inclined to spend money on an angle-of-attack indicator first, a traffic system last? Or perhaps to seek out recurrent stall awareness training? These are questions worth considering.

My contribution to the discussion is this: I'd like to see the basic understanding of stalls de-linked from airspeed and more strongly associated with angle of attack. And not just with electronics indicators, but seat-of-the-pants, fly-the-wing pitch awareness. Reliance on glass gadgets has made many of us numb to reality of air flowing smoothly over a wing; increasingly, we understand only electronic abstractions, not real physical phenomena. I'd also like to see more instructors take their students through a range of aggressive stall awareness instead of just the pro forma basic stall series.

Then there's the data itself, which is incomplete if not suspect. That's why the second big risk circle is what I call unknown or other. Even two years after the fact, the NTSB often doesn't have enough data or doesn't publish enough to judge what really happened in some of these accidents. I further suspect some of the investigations, because of lack of resources, reach the wrong conclusions. Our sister publication, KITPLANES found this to be true in the NTSB's analysis of experimental aircraft accidents. Many of the airplanes had been miscoded as experimentals, but were in fact ultralights or certified aircraft. Groups like SAFE, which are pushing for an industry-wide reduction in the fatal accident rate, have similarly called for improved accident reporting accuracy. After all, how can you fix a problem if you can't identify it in the first place?

A word about CFITs, which are also a largish risk. The classic definition of CFIT is of an instrument or night accident where the pilot flies a normally functioning airplane into rocks or trees. Depressingly, it happens in daylight, too, with whatever object eventually becomes the bulls-eye in plain sight. Year after year, these inexplicable accidents appear in the database. Some are scud runs, some are VFR into IMC, some are undershoots or takeoff accidents. But all share one characteristic: the airplane was under control at impact and probably not stalled, suggesting the pilot had options he did not use.

On a scale of one to 10 as a risk taker, I'm probably an eight. But there are people out there who make me look like your white-gloved Aunt Jane. The very first fatal accident of 2010 occurred in January when a 77-year-old pilot on his way to the United Kingdom in a Cessna 172 crashed into Penobscot Bay after he encountered extreme turbulence, having departed into a forecast that included icing. He was a multi-thousand hour experienced ferry pilot, but still, I fail to grasp any sane risk/reward in flying the North Atlantic in winter in a Skyhawk.

Despite the dodgy data, I think it's accurate enough and sufficient enough to make broad conclusions about risk assessment, especially for pilots personally. And that's to say worry less about midairs, thunderstorms and icing and more about simple, basic control of the airplane. If you combine the stall accidents with what appear to be basic loss of control accidents—in IMC or not—you account for nearly half of all fatal accidents. That's a big number and plenty to chew on to worry about things that might kill you and less about things that won't.

Comments (236)

Great article! Iviation.com has a web-based course - Risk & GA ADM which addresses some of what you are talking about.

Our course, however, addresses the Red Flags of Risk and how to assess and mitigate them.

In a nutshell, you're agreeing with the FAA/NTSB that Pilot Proficiency is the problem for the accidents. But, taken one step further, Aeronautical Decision Making or Judgement is also to blame and is the #1 cause for fatal accidents, and all to often that link is not made.

That is our goal to help in ADM, Situational Awareness, Risk Assessment and mitigation.

You are correct about stall training. It seems there is a fundamental misunderstanding of aerodynamics (amongst other topics) that are being perpetrated and that is just one of the many things that need to be corrected.

Posted by: David Perdue | December 28, 2012 7:54 AM    Report this comment

Paul, good subject. Thank you for bringing it up. I am off work for a couple of weeks so I have commented more than I believe I have ever done so in the past and I can't help linking my comments in your previous blog to this one. So, the following is all sarcasm for those that don't recognize it.

It's terrible that we've had all these not "real" pilots taught by not "real" CFIs crashing their not "real" aircraft since 2004. Oh wait, these types of accidents have happened since the beginning of flight? But how could that be? Weren't they taught by "real" CFIs in "real" airplanes and didn't they pass a medical exam?

My apologizes to those that don't get the post.

Posted by: jay Manor | December 28, 2012 7:56 AM    Report this comment

When I started flight training it was with a 'young' CFI and it quickly became clear to me he was only interested in the hours so he could move on to a 'better' job. However, I did move to an 'older' CFI who believed in the basics and really stressed flying the airplane: Looking outside, feeling how the airplane reacts to the controls, and yes we went out and actually did power-on and power-off stalls and recovery. It was a great learning experience and one that I always remember when flying.

Paul, I have to agree with you and think to many pilots are so 'involved' with the glass cockpits, new instruments, etc. that they forgot the first thing my instructor taught me: FLY THE AIRPLANE!

Aviate, Navigate, Communicate is still true today.

Posted by: Richard Norris | December 28, 2012 7:57 AM    Report this comment

Mid-Air Collisions Are Too Rare to Worry About or It is a Big Sky!

How often do mid-air collisions occur? I went to the Nall Report on the AOPA's web site to see the most recent General Aviation statistics available for 2007. The Nall Report on General Aviation accident statistics only covers fixed-wing general aviation aircraft weighing 12,500 pounds or less. It says there were only 10 in all of 2007!

Surprisingly these 10 mid-air collisions involving 20 different aircraft with 21 pilots and passengers resulted in only 4 deaths. Two of the mid-air collisions were by four aircraft involved in formation flight.

The fact mid-air collisions may be survivable is rarely written or talked about. In 2007, there were a total of 17 survivors from six different mid-airs involving 12 aircraft!

Posted by: Richard Siano | December 28, 2012 7:57 AM    Report this comment

Richard, this is the flaw in examining only the fatals, of course. And, as I noted in the text, author biases tend to skew the conclusions to the simplistic. But I think there's a place for that. My data--fixed wing only, no experimentals--found three fatal events and six aircraft involved.

Posted by: Paul Bertorelli | December 28, 2012 8:31 AM    Report this comment

I admit to NOT being a "natural" pilot. But, the good Lord has allowed me to obtain many years and hours of experience. Even a slow learner eventually gets it. I now have the feel of the airplane. When I increase back pressure on the yoke or stick, the nose comes up at a particular rate that I associate with the pressure on the stick and rate of stick movement. Clearly this is a dynamic situation that I have learned over time. But at this time, I know when I'm getting to the limit of pressure and rate of nose movement. Even in a steep turn. Although I have been instructing since 1955 and have over 4000 hrs instruction given, I still don't know how to TELL someone how to instill the integrated stick feel and nose movement in their mind - I just have to have them practice and practice until it appears to me that they "have it". It has to be learned by their finger tips and eyes.

Posted by: Bill Castlen | December 28, 2012 8:41 AM    Report this comment

I fly a Vans RV8A "Expermental" and as such was able to install a Proprietary Systems AOA, the LED readout is on top of the glair shield and has saved me more than once. I have seen lift go away at 160kts in steep turns. The unit is very educational. Just because your moving dosn't mean your flying.

Posted by: Brad Snodgrass | December 28, 2012 8:42 AM    Report this comment

I always shied away from the young instructors who were looking for airline gigs and went for the old crusty guys. My instructor was good. We did power on/off stalls ad infinitum despite the fact I tried to kill him twice (not intentionally). Being part of an Air Force Aero Club we had to fly stage checks with instructors whose sole purpose was to assess progress independently and sign-off on you. On one check I lost my engine and set up for an off-airport landing. During the turn from base to final the stall warning barked briefly and I instinctively reduced pitch. After we concluded that exercise I was chastised for a base-to-final steep turn. Being a new student with no context to measure my error and not really having practiced turning stalls, his reprimand lacked the depth to make me understand I'd probably just come close to experiencing one of the biggest aviation killers. It wasn't until later that I came to appreciate the justification of that rebuke. My long winded point is that instructors need to verify an essential message has been received and understood and not assume the student has the depth of experience to understand why we don't do that. His reaction left an impression which caused me to follow-up but it could easily have been lost.

Posted by: Robert Mahoney | December 28, 2012 8:46 AM    Report this comment

I thought you were off the air Paul? Too much family/food/bad TV? Merry Christmas from down under :-) It's 27 degrees and steamy as hell. I've got the ceiling fan on at 1am.

There was a video doing the rounds a year or two back that showed a Piper dead stick landing in a lake. Everyone got out ok. What I most vividly recall is that the pilot, in his efforts to clear the trees and glide to the lake, was holding the nose up and caught several wing drops. Despite already having enough height and speed to make a safe beeline for the water just over the tops of the lake-side trees, his instinct was to keep that nose up. He could have landed much more safely and with almost zero vertical speed if he'd kept the nose down. The lesson for me was to incorporate into my engine failure checklist two additional, non-standard items, 1. Say out loud, "Nose down if you want to live, Bozo". 2. Slap face. Sometimes I give myself two slaps to make sure I was paying attention. Happy 2013 everyone! See you at Oshkosh!

Posted by: john hogan | December 28, 2012 8:46 AM    Report this comment

I definitely believe pilots need more stall training than the current "here's a power-on stall, here's a power-off stall, and I'll show you some other stalls" practice. We practice these stalls at altitude (for obvious reasons) where we never experience the rush of the ground coming up to us, where most stall-spin accidents occur.

The eye-opener for me was when I actually had to perform the "demonstrated stalls" during my CFI training. I saw how easy it can be for a pilot to get in to a situation where they might stall the plane.

Posted by: Gary Baluha | December 28, 2012 9:18 AM    Report this comment

Paul:

It's probably not in the data, but it would be interesting to know how many anti-collision equipped vehicles fell victim to stall/spin and other more-common threats. That would be a clear demonstration of misplaced risk analysis. The same data for AOA-equipped vehicles would be interesting, too.

Posted by: Thomas Yarsley | December 28, 2012 9:28 AM    Report this comment

Rule of thumb: If it's in the news, it's not much of a risk.

This rule is true for almost anything, not just aviating. Mid-airs are extremely rare, but they're VIVID. Stalling, not so much. Fatal commercial accidents are extremely rare, and as a result they're newsworthy. As a result, many of the general public are scared to death of flying, despite the likelihood of dying being much higher driving to the airport. Ditto shootings - on any given day many more people die in car accidents, but somebody shooting up a movie theater or school galvanizes the media for months or years.

Posted by: Sat Tara Khalsa | December 28, 2012 9:41 AM    Report this comment

"I fail to grasp any sane risk/reward in flying the North Atlantic in winter in a Skyhawk." How about money. I seem to recall that 172 accident was a professional ferry flight.

Posted by: Timothy Ettridge | December 28, 2012 9:53 AM    Report this comment

I agree with your analysis about stalls. I'm lucky to have been well introduced to stalls, with lots of practice. Glossing over this in training is just bad training. However, I disagree totally with your downplaying of any type of risk. Even if mid air collisions are rare, they still happen, and can kill you. With GPS and systems that can warn you of nearby aircraft, hopefully mid air collisions will decrease. But there are still situations where a pilot ignores a warning horn / buzzer / whatever. Basically, anything that can kill you should be included in a pilot's concerns.

Posted by: David Froble | December 28, 2012 10:13 AM    Report this comment

Just fly the damn airplane. Go get some taildragger time and fly some gliders. You'll know how and when an airplane will stall then. Cover up all your flight instruments and practice real set of the pants flying.

Posted by: Gary Caron | December 28, 2012 10:18 AM    Report this comment

I noted that it was a ferry flight, which is why I mentioned risk/reward. How much would you want for the risk? I'd want at least twice what was offered, unless the offer was well into the five figures, which I doubt was the case.

In any case, the flight didn't even make it beyond the Maine coast for reasons not entirely clear in the accident report. It seems possible to me that this represents either a flawed risk assessment model or bad planning. Or both. Or maybe just bad luck.

I think we can all agree that none of us want to depend on luck. Not that I'm faulting the guy, but just noting I wouldn't do it.

Thomas, interesting question. No clear answer. Five of the fatals involved Cirrus aircraft which do tend to be equipped with traffic systems, but that doesn't mean they all are.

Two of these were loss of control, one was a stall, one was a maintenance-induced engine failure and one was...a midair. That's the one in Boulder, Colo, where an SR20 collided with a glider tow airplane and descended under its parachute on fire.

Posted by: Paul Bertorelli | December 28, 2012 10:20 AM    Report this comment

Yes, that was a professional ferry flight for a "routine" (at least in this part of the world)delivery across the pond. Problem was weather was going through and worse was to come. The pilot, like any of us, wanted to get home. I remember that day--my car was picking up ice on the way to work. Before that heavily loaded airplane could break into the clear it picked up a fatal load of ice. He put it down on a small tributary next to an island on the Penobscot River. The impact killed him. By all accounts he was a great guy, good pilot and made a bad decision. That could be any of us on any given day.

As for stalls, it seems to me that the more we practice all varieties the better prepared we are for when the chips are down so that we act automatically. It certainly pays to know where the edges are in all sorts of different atitudes and power settings and, in my opionon, a great deal more entertaining to practice than boring holes point A to B. Frankly, I think stall and non-vfr to imc loss of control accidents are more than just kissing cousins and I bet the "unknown" portion of Paul's diagram shares a good deal of both.

Some of the others are easy to avoid by exercisisng a bit of discipline: fuel, vfr/imc, cfit, convective/icing. You need to ask yourself, "how disciplined are you?" each time you confront these challenges. Discretion is the better part of valor and I don't mind being laughed at for making an unplanned/unneccesary fuel stop.(Part I)

Posted by: Jeff Russell | December 28, 2012 10:24 AM    Report this comment

Part II

So, my plea to instructors is a follows: the majority of us aren't god given gifts to the sky. When training us make us stall. A lot. Full stalls all the way to the break. Different power. Different attitudes. Lots of on the edge slow flight ending in a stall. Turning slow flight ending in a stall. Make darn sure students know what happens when you mess up that base-to-final turn (at a safe altitude, mind you). Do it again and again until they react like Pavlov's dog or the chimp in the capsule! The life you save may not only be their own, but the paying passengers in the back who have every expectation that their pilot has the proper, thoruogh training. Too many perfectly good airplanes have fell out of the sky over the past few years. Way too many. Don't wait for the rules to catch up--train for it now.

Posted by: Jeff Russell | December 28, 2012 10:25 AM    Report this comment

This article makes me feel all warm and fuzzy about getting that cheaper new transponder withot ADS-B in capability for traffic and weather. While I do keep an eye out for other aircraft, I'm one of those folks who rely on Big Sky theory to keep me from getting paranoid. When it comes to mid-airs, this really IS a situation where the drive to the airport is more dangerous: those oncoming cars are just a few feet away, there are hundreds of them, and some of them are driven by woolgatherers. As for stalls, the thing that bothers me about them is that I've done lots of intentional spins over the years (in an appropriate airplane, not my 182). In all cases, the onset of the stall/spin was such a nose-high attitude, nobody could ever get there unawares. Yet there are lots of stall/spin accidents. I've concluded other factors must be involved, and that does worry me.

Posted by: David Chuljian | December 28, 2012 10:26 AM    Report this comment

Paul ... The core point you make about pilots being focused on mid-airs when they should be paying more attention to stall conditions is valid. This is largely an issue of being afraid of what we don't know or can't see ... i.e. other planes running around unchecked in the sky. For most of us, flying is something we CAN see and we DO control (or think we control) ... i.e. flying is something we think we understand. We human's are not particularly afraid of things we think we understand and/or can control -- it's the "unknown" that we fear.

That said, it is also interesting to note how much money the government (i.e. FAA in the form of ATC) spends on insuring that airplanes remain separated from one another. Compare that to the investment it makes in ensuring that airplanes don't stall ... either as an inadvertant action on the part of the pilot OR lowering the cost of the technologies necessary to ensure that planes and pilots don't allow stalls to happen! The technology exists ... yet the government itself goes ever-onward with investments in preventing mid-air collissions while doing little more than "jaw-boning" pilots about being aware of the potential risk of stalls.

The real problem is largely cultural ... doing the same things that cause these diversely opposed issues over-and-over at both the governmental (big-scope) and personal (small-scope) levels -- while expecting change. To a great extent, government actions simply reinforce common beliefs.

Posted by: Richard Eastman | December 28, 2012 10:31 AM    Report this comment

Discussion is a part of it of course, but instruction and practical experience is an absolute necessity that is too often missing today.

Four of the five "instructors" I've used for recurrent reviews over the last 10 years were reluctant (at best) or apparently actually afraid to explore the slow-flight/stall/spin regime of flight. Three could not competently demonstrate stall recovery from any but power-off, wings-level flight. One was white-knuckled over full control deflection slips. Only one felt it was appropriate to review full stall recovery.

Each of these persons were active local instructors with pre-solo students.

As a population, how can we avoid or recover from unusual situations/attitudes if not trained and exercised in them?

H A Hough

Posted by: Unknown | December 28, 2012 10:37 AM    Report this comment

I don't think it's a simple matter of "practice more stalls" to avoid them. It's easy enough for most certificated pilots that I know to properly demonstrate the typical power-on/off straight-ahead stalls in the training (or even flight review) environment. It's the real-world situations where you see the ground coming up at you (perhaps during takeoff in an underpowered and/or overloaded aircraft) and push FORWARD in order not to stall it into the ground.

Maybe if CFIs require their students to recover from a stall "no lower than X", where X is within a few hundred feet (perhaps intentionally within an unrealistic range to induce a secondary stall, etc), it might get pilots to realize how hard it can be to fight the urge to simply pull back.

Posted by: Gary Baluha | December 28, 2012 10:41 AM    Report this comment

As certificated comtrolists, the data seems to confirm that we only fear what we cant control. We're not trained to fear stalls, but to embrace them. In fact, most lightbtrainers wont land well too far above stall aoa. Ice, midairs, lightning, electrical failures, uncontrollBle - very scary! Pass the [insert favorite av store here] catalog.

Moreover, maybe stalls should not be a causal factor. Maybe it shoud be categorized more closely with those in other modes of transportation, like "failure to pay full time and attention" to flying the airplane, which led to a stall, which led to an impact, which led to injury or fatlaity. Does skidding show up in ntsb reports on highway accidents as cause for the accident.

Posted by: Robert Henry | December 28, 2012 10:46 AM    Report this comment

Found this very interesting, and I agree with Paul's conclusions. I think a lot of pilots ARE terrified of stalls, which is why they land too fast and hold the airplane on the ground too long on takeoff. Intellectually they understand the reason for the stall is AOA but the way they're trained results in a dependance on the only way they can measure it, airspeed. The aren't taught to "fly the wing" and even though, again intellectually, they understand that the wing will stall in any attitude at any speed, they keep raising the nose when it wants to drop on it's own.

"If you want to go down, raise the nose. If you want to go down faster, raise it some more" Pop

Posted by: Barton Robinett | December 28, 2012 10:55 AM    Report this comment

Mid-air collisions are just not the same kind of problem as stalls and CFITs. The problem is avoiding mid-airs is based on seeing and avoiding other traffic. This is actually very hard to do sometimes.

When you are near an airfield or the boundary of class B or C airspace and normal airspace you face unusually high aircraft density. It is these situations where some kind of traffic information system is worth its weight in gold. I am hopeful ADS-B will provide better information than talking to the other guys at an uncontrolled field or even ATC with all their radar assistance. Many times I have come much too close to other airplanes using all the available help. The see and avoid principle is just too dependent on both pilot's vision and situation awareness which doesn't do the job very well.

All pilots can avoid a stall or spin with proper technique but avoiding a mid-air depends on other pilots just as much. I'll be happy when I have the same level of information a controller at a radar equipped station has all the time.

Posted by: Paul Mulwitz | December 28, 2012 11:00 AM    Report this comment

"I bet the "unknown" portion of Paul's diagram shares a good deal of both."

That's my gut feel. A lot of those accidents that end up in loss of control or CFIT are very likely stalls, in my view. You just can't quite resolve it from the data provided. Of course, a stall or spin is also a loss of control.

It's slowly sinking into my thick noggin that what Richard Eastman said is right: It's a cultural problem. I tend to fault pilots for these stall events. After all, how hard is it just to keep the airplane flying? Well, apparently not always that easy.

So the argument that the airplane itself has a fundamental design flaw has merit. We've made piddling attempts at stall resistant designs, but none have really made inroads. Perhaps it's time to reconsider.

John Wilson, if you're out there...this is where I need to report on your research project. I'll get that going.

Posted by: Paul Bertorelli | December 28, 2012 11:20 AM    Report this comment

I noticed a few of the commenting pilots mentioned practicing stalls with a CFI. Understanding how the approach to landing stall occurs is the best way to avoid the stall. One rule I taught was to make 30 degrees the maximum bank angle in the traffic pattern, if you overfly the final, bank 30 degrees to reestablish yourself on the final, then either go around or land on the remaining half if runway if it is long. On all planes the stall speed increases as the bank angle increases. Check section 5 in your POH to find the chart giving the stall speed in various configurations.

Posted by: Buz Oyster | December 28, 2012 11:48 AM    Report this comment

More training is the obvious answer for some, however no amount of training will get through to some personality types whether it's lack of focus or a secret belief that they are somehow a cut above, and the laws of physics do not apply to them personally, only to mere "average" people. The statistics will never change (barring of coarse some technological break through that makes it practically impossible to stall)These personalities are not limited to flying but can also be seen on the way to the airport (in your car and in any human endeavor)They will never change period...

Posted by: Steve M | December 28, 2012 12:22 PM    Report this comment

I had an AOA indicator installed in my P172D 3 years ago, on the top of the panel where it's visible with peripheral vision. After flying with it some 180 hours or so, I think a whole lot of the stall/spin scenarios would not happen, if every airplane was so equipped. I've been kidded (not always kindly) that I should be able to "feel" the airplane without it, and I agree. I can--I'm a pretty fair stick and rudder pilot, and I can certainly feel when the airplane is on the raggedy edges of a stall. But even with a docile airplane like mine, there are some kinds of stalls which can come on surprisingly quick. While I can't say that my AOA indicator has saved me, it has been interesting to see how close to a stall I've gotten at times, without any other indications (including the buzzer) other than slightly mushy controls.

Like most pilots, I love doodads--that's one of the side benefits to flying. The AOA indicator is one doodad that is more than worth its cost.

Posted by: Cary Alburn | December 28, 2012 12:29 PM    Report this comment

I have an Ercoupe and a canard aircraft (Longeze). No other airplanes are airworthy because they can be stalled and spun. Getting too slow in the Ercoupe or Longeze is unwise but that is unlikely to kill you.

Posted by: Arleigh Hughes | December 28, 2012 12:34 PM    Report this comment

Concur with Cary Alburn 100%. AOA is more than worth the cost. All planes should have them!

Posted by: Richard Eastman | December 28, 2012 12:45 PM    Report this comment

TCAS is so important that we're not allowed to fly airliners without it. When flying VFR either in or below congested class B I consider it essential. It has saved me on countless occasions in my small plane. It is expensive but it's more than worth it. The problem is, its not a very sexy item to buy. People would rather put glass on their instrument panels the way people tile their showers - wall to wall so there's nothing else. It's a foolish waste of money. I'm a 777 Captain, so I'm very used to glass, but something the size of a 496 is very adequate. Bigger is not safer, it's just bigger. Traffic solutions are very important. Save your money - buy smaller glass and put it into some sort of TCAS. No amount of training (unlike stall recovery) will suffice - you need the box.

Posted by: walker hester | December 28, 2012 1:15 PM    Report this comment

The aircraft that I fly professionally has a TCAS I, which does not allow you to deviate from a clearance to avoid collisions like TCAS II does. I have had copilots who made maneuvers based on a TCAS I readout only to find the aircraft heading towards another target not displayed on the TCAS readout. We have become too reliant on technology instead of just looking out the window! Even on an IFR clearance you are still responsible to see and avoid in visual conditions. I still fly skydivers and nothing keeps you current in stall training and awareness and slow flight like flying at minimum airspeed with jumpers climbing outside of your aircraft (c182 c185 c208 dhc-6 be-e50). We need to emphasize understanding of stalls and stall avoidance rather than how fast we can get students past this. Leave the "fire hose" method of training with the military. Having an instructor who is afaid of stalls or spins doesn't help.

Posted by: matthew wagner | December 28, 2012 2:14 PM    Report this comment

"Practicing" stall recovery is good--up to a point. Beyond that, there's a point of diminishing return. Then there is the point of realism--setting up the "takeoff and departure stall" and the "approach to landing stall" is hardly realistic--as some commentators have pointed out.

Try something different--go fly a glider. Glider pilots live on the edge of a stall all the time while circling steeply in thermals with their attention diverted. They don't have stall warners, they don't have engine power to pull them out. They simply unload the wing and continue thermaling.

That said, I also agree wholeheartedly with those who advocate AOAs. There is a lot to learn from watching an AOA--it takes into effect flap position, bank angle, G-loading--you can SEE the energy reserve you have to work with. We use them on jets, but the new AOAs (like those from Alpha Systems) cost under $1000, and installation is simple. We purchase lots of things for our aircraft in the name of safety--the AOA is the best investment out there. (continuded)

Posted by: jim hanson | December 28, 2012 2:25 PM    Report this comment

continued

The problem of stall recognition and avoidance goes back once again to outdated FAA teaching--there are countless references to "stall speed"--likely because the airspeed indicator is the only instrument common to every aircraft. It's time for the FAA to get into the modern age, and teach AOA--something that every business jet and airliner uses. AOA has other salutory effects--finding best climb and eliminating the super-fast touchdown that is a big contributor to loss of control on landing.

FAA needs a serious update of their Practical Test Standards and training to incorporate modern methods and procedures rather than continuing to teach what DOESN'T work. As an industry, we need to drag the FAA into the 21st century by demanding that our training time is spent wisely--teaching relevant skills rather than "the way we've always done it."

Thanks, Paul, for bringing this up.

Posted by: jim hanson | December 28, 2012 2:31 PM    Report this comment

Pt 1. Some of the comments here show that even in an article about stalling that tried to reinforce that airspeed is irrelevant to stalls, people still make comment about mushy controls, nose high attitudes, control pressures etc and ask how can a stall happen? All these things are irrelevant. There is only one control that determines AOA, That is the elevator. And the ONLY way to achieve a stall is to pull back on the stick. Forget nose attitude, forget airspeed. Stick (or yoke!) position is the only variable that has a bearing on a stall. Every aircraft will stall once a stick is pulled back to a certain position and that is called the "stall stick position". It corresponds to an angle of attack regardless of airspeed. The only thing that changes with respect to this is the pressure required to get the stick to that position, and that depends on airspeed. Very very few pilots understand this and even less instructors. There will be people who disagree with this citing various examples, but they will be making the common mistake of misinterpreting attitude and stick pressure with AOA.

Posted by: Dave Jardine | December 28, 2012 2:48 PM    Report this comment

Pt 2. You ask about stall resistant designs, the only way to achieve this is to simply to limit the upward travel of the elevator. Simply put an aircraft will then be impossible to stall because the stick cannot be pulled back enough (and the elevator cannot rise enough) for the aircraft to reach the required AOA to stall. That is it. Please try and not confuse the pressure required on the stick to get it to a certain pressure and definitely do not confuse nose attitude.

Practice and training will NEVER solve the stall as Paul has described it from being a major cause of accidents. At least not whilst we still teach the theory and then show in practice the flawed thinking about stalls and why they happen. Only when we change our thinking, the theory and the practice that teaches stick position as the sole cause of stalls, will we have any hope of actually reducing the number of these accidents

Posted by: Dave Jardine | December 28, 2012 2:49 PM    Report this comment

Pt 2. You ask about stall resistant designs, the only way to achieve this is to simply to limit the upward travel of the elevator. Simply put an aircraft will then be impossible to stall because the stick cannot be pulled back enough (and the elevator cannot rise enough) for the aircraft to reach the required AOA to stall. That is it. Please try and not confuse the pressure required on the stick to get it to a certain pressure and definitely do not confuse nose attitude.

Practice and training will NEVER solve the stall as Paul has described it from being a major cause of accidents. At least not whilst we still teach the theory and then show in practice the flawed thinking about stalls and why they happen. Only when we change our thinking, the theory and the practice that teaches stick position as the sole cause of stalls, will we have any hope of actually reducing the number of these accidents

Posted by: Dave Jardine | December 28, 2012 2:50 PM    Report this comment

David--we agree on the irrelevance of nose position or airspeed--but I can't agree that the stick position in the cockpit has any relevance to the AOA that the wing experiences. I can think of several exceptions:

Trim a glider with terminal-velocity dive brakes in a glide, and extend the dive brakes. The nose and the stick stay almost static, but the resultant flight path is down steeply. The result? The AOA increases to the stall point--and the stick never moved.

Example 2--Establish almost any turboprop the same glide configuration. Extend the gear and the flaps, then push the props to flat pitch. The control wheel will not move, but the resulting glide path will be so steep that the aircraft will stall with the nose well below the horizon--and the stick or yoke will be in the "normal" position.

It's part of every turboprop checkout for that very reason--people can't believe that they can be stalled with the nose far below the horizon. One more example of what you can learn by watching a real-time AOA

Posted by: jim hanson | December 28, 2012 3:15 PM    Report this comment

oh my goodness! no airplane in the world can stall unless, I repeat unless, elevator control is pulled back beyond full up-trim travel and pilot is the only, I repeat only, subject who can do that. every single pilot is always flying with his/her hand on the angle of attack indicator that is elevator control. no messing around please. forty years of flight instructing.

Posted by: Gabriel Sedioli | December 28, 2012 3:25 PM    Report this comment

That's GENERALLY true--but like all generalities, there are exceptions. Go try either one of the examples above and report back. (48 years as a CFI)

Another example--an accelerated stall in a T-38--enter at 300 knots, roll into a 60 degree banked turn and hold it--it will unhook at about 220 indicated--and the stick is NOT all the way back. So much for stick correlation with AOA.

Do what the military, the airlines, and the business jets do--buy an AOA (now that they are becoming cheap) and read the AOA out directly--forget airspeed, forget nose position, forget stick position.

What IS known is that what we have been teaching for 70 years hasn't worked--as Paul points out.

Posted by: jim hanson | December 28, 2012 3:45 PM    Report this comment

My French home built has to have a stall warner. Problem solved!! Derrick Brunt UK

Posted by: Derrick Brunt | December 28, 2012 4:03 PM    Report this comment

Pt 1. (sorry for being verbose but this is one of the fundamental problems aviation has in the world and I am passionate about it!) Jim, Thanks for the reply, Your examples, far from disproving the stall stick position actually help prove it and I thank you for bringing it up. Firstly the glider. The glider with spoilers extended has actually changed the profile of the wing and thus the AOA that the wing stalls at. This corresponds to a new stall stick position, due to a change in the lift curve of that wing. So for the glider pilot he has to know the two positions. Not really onerous. For GA aircraft that can only change their wing profile and thus lift curve by flaps the large change to the lift curve brought about by spoilers is largely irrelevant

Example 2 simply reinforces exactly what I was talking about. Nose position relative to the horizon is irrelevant. You can stall any aircraft with the nose pointing anywhere. The flat blade pitch and the undercarriage out have simply increased drag, allowing you to have a lower nose attitude without gaining speed. The flaps again allow a lowered nose attitude but do increase lift at a given airspeed, so you have effectively "raised the nose" relative to the AIRFLOW to achieve a higher rate of descent, but this also increases the AOA (by definition) thus getting you closer to the stall. .

Posted by: Dave Jardine | December 28, 2012 4:06 PM    Report this comment

Pt 2. But the only way to stall the aircraft is to pull the stick back to the stall stick position. It may be unbelievable to some pilots that you can stall with the nose in this position but the nose position itself is irrelevant.

The example you have given just goes to show that pilots were not trained and do not really understand AOA, stalling and stick position. You can stall an aircraft with it pointed vertically down and you can maintain installed flight going vertically up. Our air show performers and military jets are perfect examples of this.

The above examples you give are typical of 99% of pilots who simply do not understand why an aircraft stalls. It is not the pilots fault, it is the training we were all given and the theory we were subject to.

Posted by: Dave Jardine | December 28, 2012 4:07 PM    Report this comment

With power to idle, I can trim my PA-28-181 to full up trim (trim wheel to the stops) and it will settle into about a 500-800fpm descent rate, no stall.

If I enter a straight-ahead power-off stall and apply full back pressure/stick travel, the airplane will obviously stall. If I then release some back pressure to break the stall, then pull back too quickly, I'll enter a secondary stall with less yoke/stick travel than during the initial stall.

Posted by: Gary Baluha | December 28, 2012 4:07 PM    Report this comment

Pt 2. But the only way to stall the aircraft is to pull the stick back to the stall stick position. It may be unbelievable to some pilots that you can stall with the nose in this position but the nose position itself is irrelevant.

The example you have given just goes to show that pilots were not trained and do not really understand AOA, stalling and stick position. You can stall an aircraft with it pointed vertically down and you can maintain installed flight going vertically up. Our air show performers and military jets are perfect examples of this.

The above examples you give are typical of 99% of pilots who simply do not understand why an aircraft stalls. It is not the pilots fault, it is the training we were all given and the theory we were subject to.

Posted by: Dave Jardine | December 28, 2012 4:08 PM    Report this comment

Gary, Sorry mate but again, you have proved the stall stick position. You state in the first stall you pull the stick fully back. This is passed the stall stick position for the Archer (I fly one too!). The second time you pull back, you pull back to the actual stall stick position, thus it only "seems" like two different positions, but it is exactly the same position. Buy the laws of physics it cannot be any other position. It is physically impossible.

Guys what I have stated is not my pet theory I have simply made up. It is not well understood by many but it is an aeronautical fact. I can sit here all day and shoot down the common misconceptions and you may or may not believe it. Our training is so ingrained. But until we do change the understanding then we simply will never stop pilots from stalling inadvertently.

Everyone, please do not accept my word for it, go and challenge everything I have said, go fly your aircraft and try it (at a safe height). Forget nose position relative to the horizon, forget stick pressure, just note stick position when the stall occurs.

Posted by: Dave Jardine | December 28, 2012 4:20 PM    Report this comment

Not sure I'm buying the stick position thing. You have to account for load factor. For example, with a load factor of 1.1 in level flight, many airplanes won't need full up elevator to stall, but something a little less.

At a load factor of 1.5 in a turn, less up elevator will be required and the stick will be in a different position at stall AOA. Also, I'm not sure how you interpret stick position because it's highly complicated by sensed control force, which is variable with speed.

I think pilots generally understand why a wing stalls and can explain it, if you give them a pad and pencil. What they have trouble with is applying that concept to what they're seeing and feeling in the cockpit.

Posted by: Paul Bertorelli | December 28, 2012 4:30 PM    Report this comment

Dave--I don't believe that extending terminal dive brakes on a glider "changes the profile of the wing or the AOA that the wing stalls at." They simply add drag by spoiling lift. Though I don't have AOA on the glider, I believe that the AOA of the stall remains the same relative to the chord. As previously mentioned and agreed by both of us, the nose position is irrelevant--on this we agree. The stick position is NOT full back--but the aircraft IS stalled.

In the turboprop example--whenever I check anyone out in a turboprop, I give the example: I have the pilot trim the aircraft to approach speed in the clean configuration 3000' above the airport on a 4 mile final. I have them extend gear and flaps--then push the props to flat pitch. Even with a prior warning that the aircraft will stall, they invariably fail to lower the nose sufficiently--the nose is 10 degrees below the horizon, but the flight path of the aircraft is 30 degrees down, resulting in a 20 degree AOA. Once again, the position of the yoke is NOT fully back--it is virtually the same as when the aircraft was initially trimmed.

In the classic turboprop stall accident, the pilot might be inbound at the MDA--looking for the runway--when they finally spot it, they pull the power off and stall the aircraft--see the Sen. Wellstone crash.

The final example--the previously mentioned T-38 accelerated stall--a high wing loading--it unhooks at 220 knots--and the stick is nowhere near the rear stops.

Posted by: jim hanson | December 28, 2012 4:39 PM    Report this comment

We're getting off topic here--what Paul started out with was lamenting that after all these years of training, we're still making the same errors--the training is obviously not effective.

I advocate changing the Practical Test Standards to recognize AOA for approach guidance--rather than the emphasis on airspeed.

AIRLINE pilots, and BIZJET pilots likely haven't done a stall in years (most jets have stick shakers and stick pushers to prevent the stall) and they don't stall.

The two famous exceptions--the Colgan crew--I believe that everything they did on the stall recovery was consistent with the recovery procedure for tailplane stalling--something that every manufacturer and simulator-based course was pushing--add power, raise the flaps, pull back to stick shaker. That wasn't lack of RECOGNITION of the stall--it was mis-identifying the type of stall.

On the Air France crash, the air data system gave false information. AOA information was available--but not on the EFIS page that they had selected. Had they had that AOA information up--or a stand-alone AOA--the accident need not have happened.

While AOA information would have prevented the stalls, would practicing approach to landing stalls by the crew have prevented any one of these? Not likely.

Posted by: jim hanson | December 28, 2012 4:54 PM    Report this comment

Load factor is only a function of AOA. That is it! AOA is what controls load factor and the elevator controls AOA. I was going to write a long reply but instead just try this.

Grab your favourite instructor in a PA-28 or C172 or something with dual yokes and grab a permanent marker pen. Go for a fly at a safe height. Decrease power and pull up gradually and wait for stall break. At the exact point where the stall break occurs draw a mark on the yoke tube up against the instrument panel as a marker. Make sure you have only pulled the yoke to just achieve the stall and not passed it. This is the stall stick position. Next trim for climb, repeat the stall and note position of mark on control yoke tube. Next rack it over into a 60 degree turn, pull back until stall occurs, note position of mark. Next, trim for a power off glide then gradually pull back until stall occurs. You will be amazed.

Jim, Try it in the turboprop and the T-38. An accelerated stall is just a stall, you are just going faster and thus you feel g's. very few people have ever taken notice of the stick position but I will guarantee it is the same each time.

Posted by: Dave Jardine | December 28, 2012 4:59 PM    Report this comment

Another test, for those with an AOA indicator. Trim the aircraft for hands off straight and level flight at whatever airspeed. Note AOA indication. Now grab the stick, wedge arm against leg or side of cockpit of whatever to make sure it does not move, reduce power to idle. Do not let the stick move, wait until in stable descent and note AOA. It will be the same as in straight and level flight.

Posted by: Dave Jardine | December 28, 2012 5:03 PM    Report this comment

Jim, Further to the test I have mentioned. If you can in the turboprop (are you allowed to stall it?) set approach flaps and stall the aircraft and then release say an inch or so of back pressure to. Let the aircraft just out of the stall. The next part will require some patience. With the stick held just forward of the stall stick position, drop the gear. The aircraft will start to slow and descend at a higher rate but it will not be stalled. Next grab the prop and put into flat pitch. The same thing will happen. To aircraft will not stall. Now you will have a very low nose attitude but the aircraft won't be stalled as long as you have not moved the stick the whole time (note the pressures on the stick/yoke will change during this time. Not sure if you can do this as your stick shaker or pusher may be activated but the aircraft will not be stalled.

Posted by: Dave Jardine | December 28, 2012 5:16 PM    Report this comment

Man, this is some crazy stuff. All over the place.

If you teach a particular stick/yoke position and trim, you're not only wrong, you're doing a HUGE disservice to the student and yourself.

The student/you should be looking outside, as if in the pattern for a pattern stall or departure stall. NOT INSIDE THE AIRCRAFT.

One MUST get the feel of the tickle. and the stall. that's the purpose of flight at MCA.

The objective is to loose as little altitude as possible in a stall, reduce as much drag as possible while maintaining max lift and power and pull the nose to show positive rate of climb (usually to the horizon) max performing just short of the tickle.

An AOA gauge is fine, but most don't have it. It's not necessary. We have a stall warning horn.

Someone pointed out the T-38. Swept wing aircraft do not stall well. Their stall characteristics are completely different than what you/we fly. You cannot compare. In fact, a stall is a prohibited maneuver and Instructor Pilots (IP's) are specially trained and it's demo only.

We're making a mountain out of a mole hill here and passing along some lousy info to others.

Posted by: David Perdue | December 28, 2012 5:27 PM    Report this comment

"Load factor is only a function of AOA. That is it! AOA is what controls load factor and the elevator controls AOA."

How much time have you spent with an AOA? AOA does not control load factor--but load factor does affect AOA.

Put your aeroplane nose on the horizon. Decrease power, but hold the nose in place. AOA increases until the wing stalls. Have you increased the load factor--whether measured by the seat of the pants or a G-meter? No--but the aircraft is still stalled.

On the other hand, watch the AOA as you add flap--AOA decreases--even if you don't move the elevator. AOA changed because the wing is "seeing" a decreased angle of attack due to the change of the airfoil. That disproves the "elevator controls AOA". Another example--look at your AOA when encountering sharp-edged gusts--no change of elevator (it happens much to fast for that) but the AOA has certainly changed.

As for the turboprop scenario above--we do that every time we do an initial or recurrent checkout. Sorry--it results in an immediate stall.

"Try it in the turboprop and the T-38. An accelerated stall is just a stall, you are just going faster and thus you feel g's." G-loads have nothing to do with speed--if that were the case, Mach 2 fighters would be ripped apart. Look at any flight manual--60 degree banked turns in level flight are ALWAYS 2 gs.

Posted by: jim hanson | December 28, 2012 5:42 PM    Report this comment

One more example of the stick position fallacy--try it in a pusher aircraft with a high thrust line. In my Lake Amphibian, the power ON stall speed is HIGHER than the power off stall speed--requiring every takeoff and landing to be made with full flaps--no exceptions. When checking someone out in the Lake, I go to altitude, slow to just above a stall, and have them "freeze" the stick as you suggest--and have them add power. The aircraft immediately stalls, and will remain stalled, as the high thrust line tries to drive the nose down, and is resisted by the elevator--resulting in a stall. Reducing the power allows the aircraft to fly again as before--or the more conventional lowering of the nose.

The potential danger in flying a Lake (or any other high-thrust-line pusher--like many of the pusher LSAs) is a rejected landing over water at low altitude (perhaps avoiding a rock or log)--the pilot adds full power, he can't lower the nose or he will impact the water--the AOA is raised to critical AOA with the application of power, and the airplane starts to stall--certainly a situation to avoid.

Posted by: jim hanson | December 28, 2012 5:47 PM    Report this comment

David--the T-38 does not have a swept wing. Look at the trailing edge--it is absolutely straight. The leading edge has decreasing chord from wing root to tip--but then, so does a Piper Cherokee.

I use the T-38 to disabuse the contention that speed affects G-loading. On the T-38, 60 degrees of bank in a level turn results in the same 2 Gs as it does in the cherokee.

The stall just occurs at a faster speed than the Cherokee. The high wing loading scrubs speed quickly--but the aircraft stalls straight and true--no different than the general aviation aircraft we fly. Just unload the wing, and it is instantly flying again--no different than the glider I mentioned earlier.

As for "An AOA gauge is fine, but most don't have it. It's not necessary. We have a stall warning horn."--gliders, LSA's, and most older aircraft don't have a stall warning horn. Stall warning horns have not been effective in preventing inadvertent stalls--that was Paul's point.

Posted by: jim hanson | December 28, 2012 6:00 PM    Report this comment

*Some* LSAs don't have a stall warning. My Zodiac did.

Posted by: Jay Maynard | December 28, 2012 8:30 PM    Report this comment

For those who think stick position is what causes stalls I have a little exercise:

Take any airplane. Put it in slow flight and a steep bank, and trim for constant altitude and bank. After it stabilizes push the throttle to the firewall. Then HOLD ON.

This is one method for performing an accelerated stall. It is a required maneuver for all commercial pilot candidates. It is also the scariest thing I have ever done in an airplane - worse than fully developed spins.

If this doesn't convince you that stick position is not the cause of stalls then I just can't help you.

Posted by: Paul Mulwitz | December 28, 2012 8:34 PM    Report this comment

David ... Much of what you say is valid; except >.

If you want to compare Apples and Oranges, then a stall warning horn is often "after-the-fact" and/or with little advance notice; the AOA tells you in advance of an impending stall by bars or degrees approaching the critical angle of attack. A stall warning horn does not necessarily factor in load or weight-and-balance; the AOA does. A stall warning horn can be triggered by gusty winds; most AOA are not influenced by gusts. There are numeous other benefits to precision flying available from an AOA indicator that are simply not avaialble with a stall warning horn. Assuming you're a CFI, your statement reflects a lack of understanding of AOA indicators and their potential for increased safety.

Posted by: Richard Eastman | December 28, 2012 8:57 PM    Report this comment

Hmm. I thought the problem with loss of control wasn't so much a stall but a skid plus a stall. I thought that was the conclusion - if there is such a thing in aviation - about the Cirrus accident discussion we had many moons ago.

Posted by: tom connor | December 28, 2012 11:48 PM    Report this comment

I don't believe that focus on stall recovery procedures or AOA indicators will help with the problem. I suspect that most inadvertant stalls, whether after engine failure on takeoff or after a steep pullup or other such situations, are caused by panic. And it wouldn't matter if you had an AOA or 100 practice stalls at 3000 ft. I believe the most promising advancement may be with the use of simulators. They can't induce the panic but can at least give the sight picture and that may cause the correct response when the real time comes.

Posted by: Stephen Phoenix | December 29, 2012 12:17 AM    Report this comment

GREAT ARTICLE !!! RIGHT ON THE MONEY !!! Usually the lack of BASIC flying skills is what kills 'em, NOT That the "Sky is overcrowded"... Mid-Airs should not happen ANY at all if people would be seriously following the rules, announcing they positions on the radio and on the right frequency! Even without the folks doing just that the chance of mid-airs is so very low. And I dare say that here in Anchorage Alaska where we have airtraffic like most of yours in the "lower48" would not believe! Most of the Mid-air danger that i have seen is because of not following the rules as said above and because of pilots staring at their gadgetry and screen this screen that movin'map stuff, instead of FLIGHT THE AIRPLANE and and looking out the window. AOA's are invented for Airplanes that "Dont have a Nose!" such as the C123, the C133, MD11 etc, BUT almost all GA planes HAVE A NOSE and that now shall be your angle of attack indicator! Gee who needs an gadget in the panel while lining up that nose out there with the end of the runway !!! And sure, I think if all of us would take training in gliders and Tailwheel (conventional gear, yes) planes, basic flying skills would not be so much of a problem. Gadgetry and ADS-B will price us out of existence for sure, but it wont improve the accident rate at all. Anyway regards from Alaska...going flyin' Tomorrow!

Posted by: Lars Gleitsmann | December 29, 2012 2:44 AM    Report this comment

Pt 1. Wow, The inability of people to actually see that everything people here are talking about is Angle of Attack. Jim, Adding power to high thrust line aircraft forces the nose down, if you do not move the stick your aircraft will decrease the AOA and it won't stall, but it will initially pitch nose down. But I can guarantee that you will be sub-conciously increasing back pressure (moving stick back) to compensate thus increasing your AOA and increases your AOA thus your aircraft may stall. Lars your comment on the nose being the AOA is exactly the reason why stalls occur. The nose has absolutely no correlation to AOA. Richard, a stall warning hon most definitely does factor in load factor etc. it has to, all it sees is localised AOA at that position, thus any load factor, bank etc is irrelevant. But also due to this, it is susceptible to going off in turbulence. This occurs as that localised airflow exceeds the AOA that the stall warning horn is set to, thus it goes off. Some portion of the airflow over the wing is stalled, but the majority is not thus the aircraft continues flying.

Posted by: Dave Jardine | December 29, 2012 3:54 AM    Report this comment

Pt 2. It amazes me that people fail to see the connection between what they are doing with the aircraft and the subsequent AOA and the position of the elevator (and thus stick). Paul M, your description of what happens when you add full power in a steep turn, the only way you can stall after that is to pull further back, I have done exactly as you say many times and nothing happens if the stick isn't moved. Jim H, everything you are saying I agree with except for the fact that you are simply not making the connection between the stick and AOA. You say put the nose on the horizon, decrease power and keep it there. The ONLY way possible to achieve this is the keep pulling the stick back! Thus AOA increases and the aircraft eventually stalls. You are agreeing with me!. I do agree with David P that eyes should never be inside the cockpit. All I am trying to do is make pilots understand that there is nothing magic or dangerous about a stall and that the only control which affects it is the stick. Once people understand this perhaps they may be more consciously aware of the stick coming back as they try and achieve whatever it is they want the aircraft to do and it is telling the, through the stick their AOA is increasing and approaching the critical angle.

Thanks for the responses.I challenge all to undertake the exercises I suggested above and try and prove me wrong. One day the light will come on.

Cheers Dave J.

Posted by: Dave Jardine | December 29, 2012 3:57 AM    Report this comment

I flew the T-38 in the USAF. It is a swept wing design. The AOA was added to the 38 after years of not having one because in the final turn, you ride the buffet and there was no way to tell where the stall was. The AOA guage fixed that.

There is some really bad info being spread here.

No wonder there are so many crashes in GA.

Posted by: David Perdue | December 29, 2012 8:00 AM    Report this comment

Dave Jardin said " Jim, Adding power to high thrust line aircraft forces the nose down, if you do not move the stick your aircraft will decrease the AOA and it won't stall, but it will initially pitch nose down. But I can guarantee that you will be sub-conciously increasing back pressure (moving stick back) to compensate thus increasing your AOA and increases your AOA thus your aircraft may stall"

You are conflating two different posts. Read it again--my statement was in response to your contention that "AOA controls load factor. The post appears below.

Put your aeroplane nose on the horizon. Decrease power, but hold the nose in place. AOA increases until the wing stalls. Have you increased the load factor--whether measured by the seat of the pants or a G-meter? No--but the aircraft is still stalled.

Can you explain how AOA controls load factor in the above? Going into slow flight and stalls (the scenario above) do you feel any extra Gs?

Posted by: jim hanson | December 29, 2012 8:25 AM    Report this comment

Now to your response on high-thrust-line aircraft. My statement was "In my Lake Amphibian, the power ON stall speed is HIGHER than the power off stall speed--requiring every takeoff and landing to be made with full flaps--no exceptions. When checking someone out in the Lake, I go to altitude, slow to just above a stall, and have them "freeze" the stick as you suggest--and have them add power. The aircraft immediately stalls, and will remain stalled, as the high thrust line tries to drive the nose down, and is resisted by the elevator--resulting in a stall.

The potential danger in flying a Lake (or any other high-thrust-line pusher--like many of the pusher LSAs) is a rejected landing over water at low altitude (perhaps avoiding a rock or log)--the pilot adds full power, he can't lower the nose or he will impact the water--the AOA is raised to critical AOA with the application of power, and the airplane starts to stall

Lake factory instructors taught the above examples. Power on stalling speed is higher than power off--thus the requirement for full flaps for TAKEOFF. Doing the power on stall at altitude INCREASES the AOA. In may airplanes, you can decrease the AOA by simply adding power--the wrong procedure for high thrust lines. It is for this reason that the factory instructors caution pilots about low-altidude go-arounds--it may put you on the water when you are trying to avoid it. The same caution applies to my Kolb ELSA.

Posted by: jim hanson | December 29, 2012 8:37 AM    Report this comment

David Perdue--you are technically correct--I should have said that the T-38 does not have wing SWEEPBACK relative to the fuselage, as we think of most swept-wing jets.

I said "David--the T-38 does not have a swept wing. Look at the trailing edge--it is absolutely straight. The leading edge has decreasing chord from wing root to tip--but then, so does a Piper Cherokee.

I use the T-38 to disabuse the contention that speed affects G-loading. On the T-38, 60 degrees of bank in a level turn results in the same 2 Gs as it does in the cherokee."

The tapered wing of the T-38 (the wing is straight on the rear but decreases chord from the leading edge) technically makes it a "swept wing"--but then the Piper Cherokee, the Beech Bonanza, the T-34, and almost every general aviation aircraft would also have a "swept wing" by that definition.

The point is still correct--speed does not affect G loading--60 degrees of bank in a cherokee or a jet at constant altitude still results in a 2-G load, and stall speed increases 41%--whether in a jet, and LSA, or a glider.

Posted by: jim hanson | December 29, 2012 9:46 AM    Report this comment

We're way off topic here. But the 38 IS a swept wing and the GA aircraft are NOT swept wing. They stall characteristics are different and so is the shape.

You're correct, speed has nothing to do with the stall. Neither does aircraft attitude.

Higher altitude does effect stall speed. It increases with altitude.

But, anyway. Lots of wrong info being perpetuated here and people need to know the correct info.

I guess my next course to develop will be aerodynamics and stalls. This gives me good ammo to demystify and correct wrong info....some of which I've never heard before.

Posted by: David Perdue | December 29, 2012 10:02 AM    Report this comment

"Neither does aircraft attitude."

Wait a minute on that one. Since the wings are connected to the fuselage and stall is defined by angle of attack, attitude is not entirely delinked from stall awareness.

Almost all of the fatals resulting from stalls are nothing so exotic as accelerated or aggravated stalls, they are boring, plain vanilla 1G stalls, some with a bit of turn perhaps. (Such that we can tell.)

For this reason, I submit that aircraft attitude is one cue and one element in practical stall awareness. It's just not the only one.

When simple awareness and stimulus response is too larded up with demonstrably true but less likely exceptions, it's no wonder people are confused about stalls.

The point is this: When the boob behind the yoke senses a high pitch attitude, he needs to be aware of a possible diminishing energy state and increasing angle of attack that could lead to a stall. We need to get many pilots that far first.

Posted by: Paul Bertorelli | December 29, 2012 10:30 AM    Report this comment

I am very thankful for having an instructor who would practice stalls during almost every flight. Power on/off, while in turns, with and without foggles, during configuration changes, "trim stalls",slooooow flight to the stall, climbing turns into the stall with power etc..etc..

Now, after all that, I'm still no fan of the stall. But if your instructer is not showing you every possiable maneuver to a stall (that you or he can think of)....find another instructor. Even if its just for a flight or two.

Further, we talk about "risk takers" but we haven't discussed the other end.. I'm a cautious pilot. Probably too cautious. How can that be a bad thing? For example; as a low time pilot and durring my instruction, I have only flown in 100%, great weather. The first time I face questionable weather (not IFR, not scud running but simply not great weather) I'll be in the cockpit facing it alone for the first time....

Posted by: Robert Ore | December 29, 2012 10:44 AM    Report this comment

" the 38 IS a swept wing and the GA aircraft are NOT swept wing. They stall characteristics are different and so is the shape"

The T-38 wing is not the "classic" sweepback that we see in high-speed fighters, commercial airliners, or business jets--but it IS "swept--even though the trailing edge is straight, the leading edge tapers--making it technically "swept".

If that is your definition, then the taper-wing Cherokees, Bonanza's, T-34s, modern T-6s--all of which have the tapered wing, would also be "swept wings."

Learjets and 500-series Citations also have straight trailing edges and tapered leading edges--but you never hear of THOSE being called "swept wing."

You can't have it both ways. If the T-38 is "swept wing"--so are the others.

Posted by: jim hanson | December 29, 2012 10:59 AM    Report this comment

"Higher altitude does effect stall speed. It increases with altitude." Yes and no. TRUE airspeed will increase with altitude, but INDICATED airspeed will stay virtually the same. There may be a small factor of compressibility as you approach the speed of sound, but that is no more than 10 knots--decreasing to only a knot or two at in most applications.

From the Sabreliner training manual--"even though the TRUE AIRSPEED at which the aircraft stalls will increase as altitude increases (due to changing density), the airspeed that you read on the airspeed indicator (indicated airspeed) will be absolutely independent of altitude. It will stay the same. Or in other words, as long as nothing else changes (weight, bank angle, G-loading, etc.) altitude has no effect on INDICATED stall speed."

Posted by: jim hanson | December 29, 2012 11:20 AM    Report this comment

Getting into semantics here again--back to how to prevent stall-spin accidents? Going through the same old exercises at altitude that we've been doing since the biplane area certainly hasn't worked.

A personal experience--I flew a $600,000 Cirrus simulator for a magazine article. It had a full Cirrus cockpit. I asked the operator to let me experience ice (VERY realistic--right down to the chute pull!) engine failure on takeoff, and an approach to landing stall from 500'. I recovered with only 200' to spare--my shirt was soaked and I was breathing hard. Someone posted that we need to put the fear into pilots--this will do it!

Other than that--buy an inexpensive AOA--watch, and learn from it.

Posted by: jim hanson | December 29, 2012 11:27 AM    Report this comment

About a year ago there was an interesting blog about an engine out Cardinal that crashed and burned into a tree line after gliding the full length of a corn field. My first question was: Why didn't the pilot slip the airplane? The reaction was a stunning expression of horror and ignorance of what a slip was, how to do it and some simply stated there is no way they'd ever do a slip, "that's what flaps are for." I went to the FAA PP handbook and found they were partly to blame by describing it poorly (actually they parsed it out into 'never cross the controls except for spin entry' and in a different section 'here is a forward slip where we cross the controls).' Side slips to lose altitude are pretty much ignored bu the FAA. A web search revealed a lot of confusion in describing a forward, turning and side slip, and some got it badly wrong so I came away understanding why people don't like 'em: They don't do 'em because they don't understand 'em, and in some airplanes they are restricted. Bill Kerschner's PP training manual got it right and described them well, and the PP PTS at least describes the forward slip, probably forced into clarity by grumpy DE's.

Posted by: Thomas Connor | December 29, 2012 1:31 PM    Report this comment

I am also dismayed at the FAAs obsession with risk assessment. It has become a cottage industry with checklists of checklists that take longer to complete than the flight and ignore the obvious: proficiency and competence. Like Paul Bertorelli says: Instead of some silly-ass safety briefing on the effect of Thalidomide on my ability to care, lets go do some training on what kills the most people.

Which brings up the most bizarre of edicts from the Kingdom of safety: After an accident, we must have "A safety down day" where clueless people tell aircrew how to be safe. Argh! I like Robin Old's approach much better; "First we get drunk to celebrate the departed. Then when the facts are known, we teach how to avoid whatever caused it." An old timer once reprimanded a long winded CAP safety briefer that these are what's important to me: 'Don't hit anything; don't run out of gas; don't fly weather you cannot handle and fly it until the last piece quits moving.'

Posted by: Thomas Connor | December 29, 2012 1:32 PM    Report this comment

Years ago I taught mountain SAR for CAP using Sparky Immeson's booklet "Mountain Fury". The CAP syllabus required I spend an hour teaching how to calculate density altitude, reserve performance and stuff that only an aerodynamics engineer could love. I had suffered thru it as a student and despised it. Instead I handed out Koch charts so the crew could look up DA and suggested a minimum rate of climb as a reserve number to respect. I also suggested disposing of the crosswind chart and replace it with a little table of trig values we put on the sun visor and can use it to calculate x-wind in our heads on the theory that a rough estimate is better than fooling around with charts in the pattern. Then we spend the rest of the morning in an open discussion of Sparky's ten commandments for mountain pilots. Then we we flew some of the recommended maneuvers, such as blind canyon reversals, stalls, slow flight and steep turns while in the search for strong crosswind landings. Then debriefed the results to the group. It probably provided more discussion and learning than I have experienced in any other forum.

Posted by: Thomas Connor | December 29, 2012 1:33 PM    Report this comment

A thing about wind: I give a lot of flight reviews along the East side of the Rocky Mountain front where the wind never stops. Locals who choose to live here get it and know how to cope. Transients often have no clue, and some find mountain turbulence terrifying. A cross wind in the pattern is a serious impediment to some. When the main runway in Great Falls MT was closed in 2005 we had six beautiful tail draggers on their way to or from OSH ground loop on the crosswind runway in a three week period. I make a point of using that runway for all of our flight checks, with forward slips to both ends so they experience the difference between a left and right crosswind on a go-around. It wakes up sleepy feet, a malady many nose dragger pilots seem to suffer.

Posted by: Thomas Connor | December 29, 2012 1:34 PM    Report this comment

Finally, I see pilots do stupid things to comply with regs. The most common is getting trapped in a valley and rather than reverse course, they could have easily climbed above the rocks into IMC without a clearance and turned on the autopilot to keep the greasy side down. Not legal you say? I got to search for the wrecks, and I say they were legally dead after hitting trees, ridges and power lines in areas where there simply isn't much traffic to conflict with. The odds of even being on radar a few thousand feet above the rocks is about zero so there won't be any airliners to molest and what there are probably have TCAS. Harsh, but I think these people committed suicide by bureaucracy. As one wag put it: "If they needed to feel legal, they might mentally declare an emergency to themselves (there's nobody else to talk to), fix the problem, then un-declare the emergency. It beats the pants off a smoking hole."

Posted by: Thomas Connor | December 29, 2012 1:35 PM    Report this comment

Thomas--I like your attitude--we've become like the Europeans--rather than doing what's needed, they check with the bureaucrats to see what is ALLOWED.

It's a horrible indictment of our system, when people are more afraid of being "violated" than being killed.

Not that many years ago here in Minnesota, we had a fatal VFR-into-IMC accident. The FAA inspector allowed as how he should write up a violation for the pilot--I'd say the pilot (being dead) had been "violated" enough!

Posted by: jim hanson | December 29, 2012 1:50 PM    Report this comment

>>> Lots of wrong info being perpetuated here and people need to know the correct info.

I guess my next course to develop will be aerodynamics and stalls. This gives me good ammo to demystify and correct wrong info <<<

David, Please accept my congratulations. You have found a way to turn Internet BS from Lemons into Lemonade.

Posted by: Paul Mulwitz | December 29, 2012 2:07 PM    Report this comment

Thomas, Thank you for the intentional flight into IMC to avoid granite clouds. I never would have thought of that one but it makes perfect sense in the scenario you described. Even though I am not instrument rated I have demonstrated many times the ability to perform normal maneuvers on the gauges with no problems. It might be different in heavy turbulence (if those were cumulus clouds) but even a sloppy 180 is better than CFIT.

Just to add to the bureaucratic nonsense I have always had a great laugh over how the FAA regs go into such great detail about maintaining 1000 feet horizontally and 2000 feet vertically from clouds or one of a dozen other ridiculous statements. How is a pilot supposed to measure 1000 feet from a cloud?

Posted by: Paul Mulwitz | December 29, 2012 2:18 PM    Report this comment

The definition of a swept wing is whether the chord line is swept or straight, it isn't whether the leading or trailing edge is straight. And just to add to this, a Cherokee most definitely has a slightly swept wing in the pure aerodynamic sense. And swept wing aircraft have different stall characteristics, but they still only stall because the wing reaches critical aoa. The difference comes that in a straight wing aircraft both wings "usually" stall at or near the same time. In swept wing aircraft the one wing usually stalls first or more correctly stalls "deeper" thus you have a larger lift imbalance between the wings and it can flip over, spin etc. the swept wing design then acts to add to the imbalance rather than oppose it. But that is getting into more aerodynamics than we need here. Btw has anyone had a chance to go fly their aircraft and undertake the exercises I mentioned? Would love to hear from you.

Posted by: Dave Jardine | December 29, 2012 3:18 PM    Report this comment

Jim, To answer your question on AOA and loading, you are correct. Loading (g-forces are a function of speed AND AOA. At 60 degree angle of bank level turn ALL aircraft will be pulling 2 G. It is just the size of the turn that varies. Your T-38 stalls at 220kts or whatever speed during this decelerating 2G turn as in order to stay level as speed comes off you must move the control column back, again reaching critical AOA. It is the same with any aircraft. Swept wing or not.

Posted by: Dave Jardine | December 29, 2012 3:22 PM    Report this comment

I didn't have a question on AOA and wing loading--the response was to to two different claims--the assertion that "AOA controls the load factor" and " An accelerated stall is just a stall, you are just going faster and thus you feel g's." Neither one is correct. In the 2-g accelerated stall, the aircraft behaves just like any other, and the recovery is the same as well--just unload the wing and it is immediately flying again.

Posted by: jim hanson | December 29, 2012 3:46 PM    Report this comment

"The definition of a swept wing is whether the chord line is swept or straight". ????? How do you have a swept chord line?

Here's the definition of a swept wing--"It is the angle between the center line of the aeroplane and the line that passes through all of the 1/4 chords of the wing". Other definitions reference chord lines perpendicular to the centerline of the aircraft for measurement.

Wings may have multiple sweeps at different points in the wing. While we usually think of swept-wing aircraft as having wings swept backwards, the trailing edge can also be straight (T-38, Citation, Learjets) and the leading edge swept back--decreasing the chord as measured from the fuselage to the tip. Some aircraft (NASA X-29 and Hansa jets) have forward-swept wings.

Posted by: jim hanson | December 29, 2012 4:08 PM    Report this comment

Did you mean a chord line that is parallel to the centerline of the aircraft (but at an angle to the wing)? I'd buy that.

Posted by: jim hanson | December 29, 2012 4:11 PM    Report this comment

Pt 1. - John – unless your an aero engineer, you don't understand swept wing. By your definition, no fighter other than those in Korean war era are swept wing. Most fighter wings typically don't have much of an airfoil shape and and lift is not being produced by the design but propelled by the power of the engine.

The 38 wing is like the 4, 5, 15, 16, 18, 22, 35 wings and I could go down the line of Soviet fighters and the Euro-fighter as well as Mirage and so on. They're shaped like that so the aircraft can go thru the sound barrier. They stall from the wing tip inward which is opposite GA aircraft.

The reason for the AOA in the fighters, initially the fighters, was because it stalls from the wing tip in, you lose aileron effectiveness quickly, thus the need for the AOA gauge. In the 38 in particular, in the final turn, you were always in the moderate buffet (we referred to it as elephants dancing on the dash). The AOA gauge helped identify the optimum angle signified by the green O. The red chevrons pointed up or down showing to release or add back stick pressure. Same in all fighters and same in the heavies.

You do not fly by AOA gauge, you fly by feel, cross-referencing the gauge.

Posted by: David Perdue | December 29, 2012 4:45 PM    Report this comment

Part 2 - There is really no need of an AOA gauge in a GA aircraft. They're typically stable (unlike swept wing aircraft which are unstable ) and easy to recover with minimal altitude loss and no hysteria.

Paul Let me clarify "Attitude". In GA, a stall is typically thought of from basically straight and level flight. When I say attitude, I'm talking about upside down, straight up, straight down, doing whatever.

In the military, we called it unusual attitude recovery, in GA it's called upset recovery. Basically in the trainer and fighter world, we were always in upset recovery mode and max performed the aircraft – always. Always by feel. Eyes out of the cockpit!!!

If anyone was ever caught "pre-positioning" the stick or yoke in stalls, you automatically hooked – FAILED – the ride. Period. Whether the recovery or the setup. It builds in bad habit patterns that are wrong and get you killed in different situations. Any instructor who teaches this should be de-cfi'd!

Jim – agreed on TAS and altitude. That’s what I was referring to.

A stall (unless the aircraft is prohibited) is not something to be feared. Too many CFI's fear it and perpetuate that fear down the line. I flew with a guy a while back who is a Gold Seal CFI with 3,500 hrs and he was scared of stalls. Nor could he correct for winds in holding or tracking. But I digress…..

A stall can be any airspeed and any attitude. The only thing that matters, is the CRITICAL ANGLE OF ATTACK being exceeded ?

Posted by: David Perdue | December 29, 2012 4:47 PM    Report this comment

Part 3 - Again, you CANNOT CONFUSE ANGLE OF ATTACK with aircraft attitude!!!!

Stalls are safe! Unless prohibited! Or too close to the ground!

AOA has zero to do with load factor. Wrong info again.

An accelerated stall has zero to do with speed either. It is simply exceeding the critical angle of attack. I can do it at 70KIAS or 120KIAS. It is simply setup clean and in a bank - like greater than 60 degrees is all. No big deal. Just simply release some backstick pressure until the burble goes away. Nothing scary. Nothing dangerous.

Dave, not sure where you get your info on g's being a function of speed and AOA. Yes on 2g's at 60 degrees of bank but not following the rest of what you're saying.

Dave, you're way off on the stall characteristics of swept / straight wings. Read what I said above again. Way off. So way off.

Posted by: David Perdue | December 29, 2012 4:47 PM    Report this comment

As for RISK - in a way I agree and in a way I disagree. The reason I disagree with you is because the level of knowledge in GA is so low and ADM and SA so poor, that this is a major step in getting GA pilots to have better SA and thus better ADM.

Without a sound understanding of Risk and how to control or mitigate it, you cannot have good SA or ADM

Take our course on Risk & GA ADM. If you don't like it, I'll refund your money.

www.Iviation.com

Posted by: David Perdue | December 29, 2012 4:49 PM    Report this comment

To clarify my comment on 2gs at 60degrees of bank - thats only if it's in a level unaccelerated turn. I can be in 60 degrees of bank flying straight and still be at 1 g.

G's is about Gravity. the resultant vector and if you want, I can get technical with this explaining it. But if you're not in a level, 60degree banked turn, you won't get the 2 gs. You can have 1, or 0 even.

Posted by: David Perdue | December 29, 2012 5:10 PM    Report this comment

" - There is really no need of an AOA gauge in a GA aircraft. They're typically stable (unlike swept wing aircraft which are unstable ) and easy to recover with minimal altitude loss and no hysteria" I would disagree with you there--and apparently, so would the FAA. In only the past few months, they have started advocating the use of simple AOAs--it explains what is actually happening to the wing far better than an airspeed indicator.

General aviation uses for AOAs are VERY much needed. Unlike any other instrument (or "feel"), they give a direct reading of lift reserve--how close you are to the stall. Fly the WING--and the only instrument that tells you what the wing is doing is the AOA. It takes into account weight, density altitude, power loading, wing loading, flap position--NOT by a super computer, but by actually measuring what the wing is doing--Angle of Attack.

continued

Posted by: jim hanson | December 29, 2012 5:16 PM    Report this comment

Continued AOAs are useful in training--they help teach a student exactly what the effects of bank, load factor, power application, flaps, and sharp-edged gusts have upon the airfoil. They allow GA pilots to know just how close to the stall they are operating. Flying the AOA eliminates too-fast approaches--a leading cause of overshoots, bad landings, and loss of control on landings. The AOA works, while the airspeed lies.

I know your background is Air Force, but the Navy teaches AOA control of the airplane--and they know a thing or two about operating at very slow airspeeds and high Angles of Attack. I wouldn't dismiss AOAs--the FAA, the military, and the bizjets believe in them enough to invest in them--why not GA?

Posted by: jim hanson | December 29, 2012 5:16 PM    Report this comment

Jim, I did an exchange tour w/USN & flew the A-4 as well for a short period of time.

I'm not saying don't get an AOA. What I'm saying is they're not the end-all. The FAA is not always right either. But I won't go there, here.

A stall is being made out to be much more than it really is in a GA aircraft. I had some 2,000 hours as CFI, CFII, corp pilot and freight pilot prior to USAF. many many years ago. So, I'm not coming at this from a purely military perspective.

Stalls are no big deal. They're made out to be and a lot of bad and wrong info and techniques are being passed down, some of which can get people killed.

It's a great topic, but I'm shocked at the fear, misunderstanding and wrong info being shared. Not just here, but in the system.

As for the Navy teaching AOA control of the jet, not per se. Just like the USAF, you're flying an optimum AOA the AOA gauge simply tells you where that point is. If you're not flying the correct airspeed, it's irrelevant.

SO, to your point about the airspeed lying, that's wrong. The AOA can lie too. You set the pitch and power, trim off the pressure and make small adjustments for airspeed and AOA in the decent. I can be 25 knots fast on final and my AOA gauge will read in the green.

Posted by: David Perdue | December 29, 2012 5:34 PM    Report this comment

You MUST use your airspeed indicator. It only lies when there is a problem like ice or such. same with AOA. if your AOA gauge is not heated, what can happen? If you got wrong info, your flying wrong. That's the cause of bad SA and ADM and accidents/incidents.

Posted by: David Perdue | December 29, 2012 5:34 PM    Report this comment

You MUST use your airspeed indicator. It only lies when there is a problem like ice or such. same with AOA. if your AOA gauge is not heated, what can happen? If you got wrong info, your flying wrong. That's the cause of bad SA and ADM and accidents/incidents.

Posted by: David Perdue | December 29, 2012 5:36 PM    Report this comment

Paul Mulwitz: Thanks for the attaboy. Years ago Richard Taylor made an audio tape of the FAA silly stuff as you mention, plus the intermingled statute vs nautical mile and other things pilots are expected to estimate accurately with no training in estimating accurately.

I once took a group of pilots on tour of the tower and we played the game of 'how far and how tall is that?" We handed sheets out with a list of objects near and far and the pilots marked the estimated distances and heights. Then we compared our answers to the tower's measured data. Its pretty obvious that pilots are damn poor judges of distance.

I also rode around with a bunch of controllers in AWACS, and one of the guys that moved from MacDill to OKC joked that controllers would visually pack the airliners onto the ILS into Miami. the joke was that one pilot asking what his separation was behind another jet in the conga line and the controller answered 'about a mile.' Later with the two taxiing down the same alley a few feet apart, the AC once again asked for separation and the controller said "about a mile."

Maybe the definition of military precision has a place here: Measure it with a micrometer, mark it with chalk and cut it with an ax.

Posted by: Thomas Connor | December 29, 2012 5:41 PM    Report this comment

A bureaucrat can only deal with the quantifiable,silly as it may be. That's why we see silly stuff like the lack of a filed flight plan on accident reports for a touch and go sortie. Mechanics are a lot like that too: If the disk rotor is .000005" too thin it's 'un-airworthy.' And the term 'airworthy is not all its cracked up to be when you get to work with stuff that has been declared as such.

On the other hand, a pilot works in the real world of old wives tales, opinions and theories (which produces lift: Bernoulli or Newton? What makes planes go up: Pitch; power; Money or fuel? Which is better: LOP or ROP? Which deters bad guys: A trained shooter or a sign on the wall? How strong are the winds? Is this ice a light trace, moderate trace or heavy trace? is the turbulence light chop, moderate chop or extreme chop? And don't get me started on RCR.

A certain gallows humor works too. Briefing to passenger in a fighter jet: Don't touch anything that has the paint worn off: Its important and you might affect the flight. And for sure don't touch anything with dust on it, for we don't know what it does.'

Posted by: Thomas Connor | December 29, 2012 5:41 PM    Report this comment

A note about stall warners. At least in Cessna 100 series: I can spin a C-150, 172 177 and 182 for three turns to the right by applying full right rudder BEFORE the stall horn comes on. I have not allowed the spin to stabilize but assume the stall horn might then come on later in the spiral. (Those with experience feel free to respond).

I'm told this is because the stall horn duct or switch is only on the left wing because P-factor usually makes a departure from controlled flight go to the left, so the left wing retreats and stalls first. A yaw to the right stalls the right wing while the left never stops flying - hence no stall horn. Would an AOA indicator show a loss of reserve before loss of control? I dunno. Pile on guys!

Posted by: Thomas Connor | December 29, 2012 6:01 PM    Report this comment

Thomas you bring up a great point on spins and AOA. But I'm going to my daughters basketball game.

Posted by: David Perdue | December 29, 2012 6:05 PM    Report this comment

I will have to admit that I have not read every word of all the comments but scanning though, I haven't seen fear of hitting the ground as a reason for stall / spin accidents. If you have ever been in a situation close to the ground, been distracted, lost airspeed and had a wing stall, usually the nose will drop. It's a shock! The conditioned response is to pull the yolk back leading to a spin. How do we train pilots to react by adding power and pushing the yolk forward and not pulling back when they the ground rushing up at them?

Posted by: Dana Nickerson | December 29, 2012 6:18 PM    Report this comment

Dana: Without knowing what you are flying it's a guessing game, but I don't know of many FAA certified GA airplanes that stall/spin without some warning unless you are trying to make it do so. Recall that flying is a balancing act. Certification requires that you can trim a plane for a huge amount of pitch stability. Sadly, the rules don't apply to roll. A plane that is unstable in roll can be a handfull. Most have ground or air adjustable aileron tabs to allow for a heavy wing or screwy load so it flies straight hands free. Factors such as mis-rigging, bent wings or fusalage, or assymetric wheel fairings or wingtips can also act as rudders that mess with stability. It could be something as simple as another 300 lb solo pilot set an aileron tab to offset the imbalance. Look for the obvious.

Posted by: Thomas Connor | December 29, 2012 8:12 PM    Report this comment

Dana continued: First, never ever ever push on the yoke close to the ground. Relax back pressure for sure: Add enough power to arrest the descent if you have it, and if you don't already, get the plane in a pitch attitude so it prangs on the main gear if it comes to that. And use your feet! If a wing drops get the rudder under it. Practice dutch rolls to learn about adverse aileron yaw and rudder.

Don't use full flaps unless necessary. Look at the POH and note the difference between full and no flap landing roll for your ride. For most GA planes the difference is minimal, but the cost in handling is high because flaps make the plane more nose heavy and invites nose-first arrivals with all the bad things that can produce. Add that to a nose heavy airplane with two up front and empty back seats and you'll run out of nose up trim to control descent. Get too slow and you MUST carry power to blow the tail down or it will stall. Not the main wing, the tail.

Posted by: Thomas Connor | December 29, 2012 8:26 PM    Report this comment

>>> I can spin a C-150, 172 177 and 182 for three turns to the right by applying full right rudder BEFORE the stall horn comes on. I have not allowed the spin to stabilize but assume the stall horn might then come on later in the spiral. (Those with experience feel free to respond). <<<

I took spin training in a 150 (or was it a 152?) and I couldn't get it to spin at all unless I kicked hard left rudder while popping the throttle as the plane stalled. I don't think that plane could spin to the right.

Very funny - the story about the worn paint and dust . . .

Lastly, My Zodiac XL has an LRI (Lift Reserve Indicator) which I made when I was bored waiting for a sub-kit. It is very helpful at low speeds but I'm told it is not actually an AOA. Anyone who doesn't need certified stuff in their plane can get the design for the LRI by searching the web and can make one for much less than $100. I find it a real confidence tool when making slow turns in the pattern.

Posted by: Paul Mulwitz | December 29, 2012 8:27 PM    Report this comment

Dana continued: Get some instrument training: It'll teach how to compare the sight picture outside to the gages, so when distracted a glance at the gages will tell what's happening in your absence.

And learn to trim for instrument flight, ie, hands off or fingertips only. Trim is the 4th control in the pilot's tool kit. Use it with every power change and it's hard to find yourself in any 'sudden' loss of control.

If you are in the habit of landing on the nose gear stop doing it: Learn the sight picture that lands on the mains. Show off by having the trim set so you can hold the nose off until the tail is done flying. Yes, being trimmed this way makes an abort a handfull, but fly the approach with minimum or no flaps and it negates the trim. My opinion is that it's a hobson's choice, and trim for landing allows fine control in the flare and a hand on the throttle where you need it most.

Posted by: Thomas Connor | December 29, 2012 9:16 PM    Report this comment

Paul: I did spins in a 1967 Cessna 150, with a hard kick on the right rudder pedal it spun to the right instantly. Possibly a difference in aircraft rigging? The one I spun had a hard life in the training world. Throttle was at idle, no "popping"of throttle required.

Posted by: Joe Sikora | December 29, 2012 11:12 PM    Report this comment

Joe - it was many years ago that I did the spin training. It might have been a 152. I don't think there are any differences between 150 and 152 except engine change and flap reduction from 40 to 30 degrees. However, they might have fooled with the rudder displacement too.

Posted by: Paul Mulwitz | December 29, 2012 11:34 PM    Report this comment

David P, Sorry but you are very very wrong. You have obviously been around a bit and from what you have written are an aeronautical engineer (as am I for 20+ years) as well as a pilot I am very very surprised at your comment. Your statement that g forces have nothing to do with AOA is blatantly wrong. How can one impart any change to an aircraft if not through a change in AOA. That change in aoa is felt as a force to the occupants of that aircraft. You even say this with the comment about being in a 60 degree bank, but not turning, you will only have 1 G on the aircraft. This is 100 percent correct, but you failed to mention you would now be descending. If the rudder was powerful enough (and the engine produced enough power) you could apply top rudder (and opposite aileron) to maintain level flight and the 60 degree bank, thus i fully agree you could fly level in a 60 degree bank and feel 1g but other than air show performers and aerobatic pilots (I do have a little experience in this) why would you bother?

Posted by: Dave Jardine | December 30, 2012 2:22 AM    Report this comment

Continued If you are doing a level 60 degree banked turn, the only way you can do this is through pulling back the stick, and applying aoa to maintain level flight. The 2Gs felt by the pilot is simply a function of requiring that amount of force within the resultant lift vector to provide the equivalent of the aircrafts weight vertically to keep the aircraft level, but you know this. This force is a result of an angle of attack applied through the elevator by the pilot pulling back on the stick. So if it were not for aoa you could never EVER change direction of an aircraft let alone takeoff and descend.

Posted by: Dave Jardine | December 30, 2012 2:24 AM    Report this comment

Continued. As for the characteristics of swept vs straight wing I am most definitely correct. What have I said that is incorrect? The discussion here is not technical at all and I am sure we can agree when it comes to the technical side (we are probably trying to say the same thing but i am explaining myself badly) But for the layman and pilots here I try and keep it simple/easy to understand. Thus my original comments that there is only one stall stick position and if pilots are aware of it then it is may belief we would have less stall/spin accidents.

Posted by: Dave Jardine | December 30, 2012 2:25 AM    Report this comment

Continued The reason I am very confident in this is as Paul originally said, even with all our modern equipment, modern ways of training, the good old stall accident rate is essentially unchanged for however many years. Thus continuing to do the same thing and expect a better outcome is -well I think Einstein said it best - the definition of insanity is doing the same thing again and expecting a different outcome. Training definitely comes into it, but why not try something new rather than just say more of the same is required? As I said at the start, aviation is so ingrained any new ideas (stall stick position is not my idea but I do agree with it because it is correct!) are immediately jumped upon as wrong/bad/dangerous or whatever. In this case it is simply not understood.

Posted by: Dave Jardine | December 30, 2012 2:26 AM    Report this comment

Continued I have tested the stall stick position theory in at least 20 different aircraft and it works with all of them. (admittedly not a Lake with a high thrust line, that has me intrigued and I take Jims word for it that it will stall with the application of power and no change in stick position - even though this goes against all my aeronautical engineering training to see how this is possible). Why does it work? Simply because the only control a pilot has to control AOA is the elevator - and stalls only occur by reaching a critical AoA. You can only reach critical AOA by using the stick. Anyway I wish there was a better forum for this discussion as a 1500 character box is simply not enough to fully answer all the comments made here, all of which (bar the comment on the Lake) I know to actually be supporting what I saying. I would just like to be able to educate people to make the connection between what they are seeing and doing in the aircraft and the elevator and thus AOA. I will leave this alone now as we have all done it to death, but I do welcome any comments on anyone brave enough to undertake the little in aircraft exercises I talked about earlier. Don't be afraid, have a go, you WILL be surprised. Respectfully Dave J

Posted by: Dave Jardine | December 30, 2012 2:27 AM    Report this comment

A stall can be any airspeed and any attitude. The only thing that matters, is the CRITICAL ANGLE OF ATTACK being exceeded ?

Dave, you are, to a degree, building unrealistic expectations for the pilot community at large. The state of training these days is such that we barely have the money, time and resources to convey to new pilots the very basics of aerodynamics. If we expect them to master--and respond to--stalls from departed attitudes probably up to and including accelerated stalls, we're lost. It's not gonna happen.

That's the stuff of high-level upset training and some pilots pay the money to get that training. I have reviewed hundreds, if not thousands, of these and the vast majority are simply sunny day pattern-type accidents in which the pilots simply stalled in near 1G flight. Evidently, the pilots were unaware of their diminishing energy state by ignoring pitch and airspeed cues. If you can at least keep them in the loop on that, without cleverly showing them how you can provoke stalls in all sorts of exotic flight attitudes and energy states, you have succeeded mightily.

They don't need 400-level cockpit physics to do this. The 10 percent--or whatever--of pilots who provoke exotic stall accidents are probably hopeless. And by exotic, I mean one like this: www.snipurl.com/25zysln. There aren't many of them.

Posted by: Paul Bertorelli | December 30, 2012 6:53 AM    Report this comment

The point is this: pilots understand the angle of attack thing. It's simple. Really simple. They can draw the diagram and put in the 17-degree arc. What they lack is the ability to understand and *respond to* the angle of attack cues. One of these airspeed, one is attitude, one is load factor/bank angle.

AOA indicators are a great idea. We've analyzed and compared them no less than five times. We've sung their praises, but they'll have no impact on stall accidents unless people buy them in sufficient volume, train and use them. But they won't do that. I'm not sure why, but they won't. Even the OEMs haven't provided AOAs, although they easily could.

So we work with what we've got.

Posted by: Paul Bertorelli | December 30, 2012 6:54 AM    Report this comment

"Dana: Without knowing what you are flying it's a guessing game, but I don't know of many FAA certified GA airplanes that stall/spin without some warning unless you are trying to make it do so."

And therein lies the core of the problem. Pilots don't realize they're trying to stall the airplane because they miss the important cues in flight regimes where they are just doing normal things like taking off or flying the pattern. They don't hear the horn, feel the buffet or notice a wing drop because they aren't expecting it and don't have antennas tuned to sense those low-energy states of flight where the risk is elevated. Perhaps some of those pilots can't even be trained to develop that skill. It's possible.

I'm sure Dana will tell the story as he has before. We are former airplane partner in a Mooney 201. One of the drills I do in that airplane--all of them, really--is a post takeoff engine failure. The response I've always taught is Pavlovian: lower the nose immediately, regardless of what's ahead. If you don't do that, you're not going to be in the game long enough to do anything else.

Dana had call to use it. In 2002, the Mooney engine quit just after takeoff and he put it, under control, into a salt marsh. Three people aboard, no injuries. The airplane was a loss.

Posted by: Paul Bertorelli | December 30, 2012 7:10 AM    Report this comment

We can discuss what is probably a semantic point, but I have always taught this response as a sight picture thing. There's no time to look at the airspeed indicator, so lowering the nose to just below the perceived horizon is a starting point that will keep the energy from decaying irretrievably. In my experience, this is a definite gentle pushover, not just relaxation of back pressure. But I suppose you could say they are one in the same. Either way, it is something a pilot can perceive *and perform* under duress without thinking about AOA or airspeed.

I do know this from trials in many airplanes: After takeoff, if the power goes, you have about a second, maybe two, in that high AOA regime before the sudden loss of thrust will provoke a stall or a mush.

The scenario isn't necessarily the biggest stall cause/result, but it's certainly in the top three. If we could train up on just this one scenario, we would probably save a few lives every year.

Posted by: Paul Bertorelli | December 30, 2012 7:27 AM    Report this comment

David Perdue--As for the Navy teaching AOA control of the jet, not per se. Just like the USAF, you're flying an optimum AOA the AOA gauge simply tells you where that point is. If you're not flying the correct airspeed, it's irrelevant.

Have you spent time recently with active Navy pilots? I spent 4 days on the Abraham Lincoln to do a magazine article. I talked to COD drivers, Hawkeye, and F-18 pilots. All said they use the AOA on landing--exclusive of airspeed. The AOA is in the Heads Up display, and on the glareshield. No time to look for airspeed approaching the deck.

Here's another example: Spend some time on the Landing Safety Officer position on deck ("Paddles"). Each approaching airplane has a dim light on the nosegear--I thought it was a landing light (it isn't--they don't use lights on landing). It's linked to the AOA in the cockpit--it shows RED if the aircraft is too fast coming aboard--and if the LSO observes the red light, they wave off the pilot. TOTAL dependence on AOA for speed control.

Posted by: jim hanson | December 30, 2012 8:26 AM    Report this comment

David Perdue--"SO, to your point about the airspeed lying, that's wrong. The AOA can lie too. You set the pitch and power, trim off the pressure and make small adjustments for airspeed and AOA in the decent. I can be 25 knots fast on final and my AOA gauge will read in the green."

Have your AOA adjusted. An AOA measures EXACTLY what the angle of attack is--so fast, that it will IMMEDIATELY move with the application of power, the addition of flaps, change in G load, and even sharp-edged gusts.

David--"You MUST use your airspeed indicator. It only lies when there is a problem like ice or such. same with AOA. if your AOA gauge is not heated, what can happen?"

Every AOA I've seen is heated. The chance of the AOA heat going out is the same as the chance that the pitot heat goes out--what's the difference?

Airspeed relies on air being packed into pitot tubes--and must be "adjusted" for aircraft weight, flap, power, and air density. AOA reads conditions directly. Airspeed is only an approximation.

Posted by: jim hanson | December 30, 2012 8:36 AM    Report this comment

Paul Mulwitz--" My Zodiac XL has an LRI (Lift Reserve Indicator) which I made when I was bored waiting for a sub-kit. It is very helpful at low speeds but I'm told it is not actually an AOA. Anyone who doesn't need certified stuff in their plane can get the design for the LRI by searching the web and can make one for much less than $100. I find it a real confidence tool when making slow turns in the pattern."

Paul--did your LRI have a vane--like the stall warning vane on earlier Cessnas? Safe Flight (the same people that make the stall warners) made them in the 1960s--but couldn't get them FAA-approved because they weren't a "real" AOA. Beech used to include them in King Airs through the B-90 model. They only sensed the stagnation point on the wing leading edge, and provided only "fast/slow" information--but they were VERY effective. It prevented an accident on one of our B-90s after the static ports froze up--airspeed indications were high, but the pilot cross-checked the indicator, and found his "pseudo" AOA too slow. He added power on short final, BARELY averting the stall.

FAA, this summer, issued a letter approving low-cost AOAs on GA aircraft for advisory purposes. University of North Dakota, and several other universities, are building them into their training programs.

Posted by: jim hanson | December 30, 2012 8:45 AM    Report this comment

Dave Jardine--I knew I had heard the "stick position" postulation before--so I looked for it last night and found it in "Stick and Rudder"--page 160. Langewiesge, in his 1944 book, proposed the same thing--lauding "foolproof" aircraft with limited controls. He also identified the problems--pitch authority is different power on and power off. A restricted stick movement may limit the ability to raise the nose on landing--resulting in limited CG range. He also cites "when an airplane is only near the stall, misuse of ailerons and rudder may still induce a spin." He cites possible cures for that--eliminating rudders, or mechanical stops for the ailerons and rudders.

He jokes that the stall problem could be cured with 10 cents worth of wire to limit controls--IF you can solve the problems above. The Ercoupe didn't fare well in the sales arena.

"Fly-by-wire" aircraft attempt to limit control electronically. Do we really want to have that in GA airplanes?

Posted by: jim hanson | December 30, 2012 8:59 AM    Report this comment

Jim, I'm not sure what a vane is but the device you describe sounds more like a stall warning device than a lift reserve indicator.

Take a look at www.ch601.org/resources/aoa/aoa.htm

This system consists of a rectangular block of aluminum used for a sensor, some tubing, and a differential pressure gauge. It gives continuous readings, just like an AOA, when you are flying slow enough for it to work. At cruise speeds the needle is pinned to the top of the scale.

According to a friend who makes and sells AOAs it is not an AOA. I think his reasoning is it doesn't read out in degrees - just relative lift reserve. From my perspective the difference is not important.

I like to use the LRI in those base to final turn environments where I am low and slow and need to correct my flight path to line up with the runway. I know this is exactly the place where most deadly stalls occur. The indicator is mounted on the top edge of my panel where it easy to see with a quick glance.

Posted by: Paul Mulwitz | December 30, 2012 9:45 AM    Report this comment

Maybe there should be more 'slow flight' training in the PPL training syllabus and a 'slow flight' exercise as a mandatory part of the BFR. I think any pilot should be able to demonstrate flying level at just above the stall speed and then performing co-ordinated turns to 30 degrees or so and being able to take the aircraft into an incipient stall and out again at will. I get the feeling from talking to some pilots that they would be very apprehensive about doing this. And that's worrying.

Posted by: Ian Walton | December 30, 2012 9:59 AM    Report this comment

Paul B: Thanks for the correction about pushing the yoke with an engine failure: You're right: It has to be positive and quick. I was thinking Dana was a newbie who hadn't learned to trim yet and looked at it as a stall on approach, not departure.

I do the same power cut drill as you - likely learned it from you along with training 'when the whitecaps are on the coffee pot.' It startles others so much that unbriefed and uninvolved observers reported me to the feds. It's a big angle change from Vx to whatever it takes to keep it flying, and I find it better to introduce with a power reduction on climbout until student and observers can handle a power cut.

Posted by: Thomas Connor | December 30, 2012 12:29 PM    Report this comment

Paul M.--it was made by Safe Flight--the same people that made stall warning vanes. I've seen the Lift Reserve Indicator--the "new and improved" commercial version of it is Alpha Systems www.alphasystemsaoa.com/ They have an informative website. I did a magazine article on them--it is their system that the college programs are installing.

They have self-powered systems like the LRI for aircraft without electrical systems--they have displays like a military or bizjet--but the best systems incorporate LEDs on the glareshield mount where your peripheral vision detects not only the color, but the trend on the remaining lift.

Posted by: jim hanson | December 30, 2012 12:42 PM    Report this comment

AOA vs stall: Isn't there a big difference in behavior between props and jets in the stall?

Most jets blow air behind the wing. Most props blow air over the wing and tail, inhibiting stall beyond the published AOA and improving stall recovery. How much? Not sure, but I can do a 'falling leaf' maneuver in my Cardinal (power off stall, yoke all the way back to the stop and walk the rudder to keep wings level in the sink). A burst of power arrests the sink to zero with little change in yoke position (admittedly I can rarely hold it very long with power on because P-factor wins). I also don't recall if the air blast changes actual AOA or IAS, but as far as the wing and stabilator are concerned the airflow has changed enough to level off.

The USAF had some 'blown wing' jet prototypes built in the 70s to see what the advantages might be, but drag was a problem. en dot wikipedia dot org/wiki/Boeing_YC-14

Posted by: Thomas Connor | December 30, 2012 12:54 PM    Report this comment

I fly in the Vancouver, British Columbia, Lower Mainland, area. We have here 8 land airports and 4 water-based landing facilities, plus several off airport helicopter landing pads. Two of the airports are international scheduled airlines airports, three are towered training facilities, two are uncontrolled airports, and one is an ultralight field. To add to the mix, we have here three designated flight training areas, one designated aerobatic training box, glider base at one of the airports, and a skydiving field; all of this in less than 20 miles radius. With all these airports around, the available flight corridors sometime feel like I-405 during LA traffic rush. At times I am number five or six for landing, and looking for traffic, while being vectored around. Am I looking at my instruments? No, no time, too busy looking for traffic. I was fortunate to have an instructor who did not put his money on instruments much. He believed firmly in flying by the way the aircraft feels; however, I have to come clean, I am a gadget guy with a very well equipped aircraft. There are often times when I really can't afford to look at the gages much, though. Thanks Mr. Millbanks for teaching me flying your way; however, and admittedly, flying was simpler then. Gadgets were not as important as they are today. I got my ticket in 1972, and I am 68. Am I concerned about mid-airs? In our local flying environment, you can bet I am.

Posted by: Edward Dolejsi | December 30, 2012 1:01 PM    Report this comment

So--back to the initial question--What do we do to correct one of the leading causes of accidents?

We could do more PRACTICE--but that hasn't worked in the last century. Kind of like Communism--hasn't worked anywhere it's been tried, but people keep trying.

We could continue to simply say "Don't do that"--but that doesn't work, either.

I WOULD like to see more slip training, as someone mentioned. It shouldn't be feared.

I'm in favor of trying an educational program in the new simulators--it was VERY realistic in the Cirrus--but they won't reach all pilots.

I really believe that widespread adoption of AOAs will help, now that the FAA is on board. It will not only give direct readings, but it will educate pilots as they see what is actually happening on the wing.

Posted by: jim hanson | December 30, 2012 1:02 PM    Report this comment

AOA simply measures the angle of attack and in the green, shows optimum angle. It has no relation to G's.

Thomas, other than swept wing design, like in fighters, the jets (I also flew the C141) stall characteristics are the same. They're stable aircraft design, not unstable. They stall from the wing root out which allows the aileron effectiveness to be maximized thru the stall. Swept wing stall tip in and that's why we don't practice stalls (or spin) in swept wing aircraft.

Posted by: David Perdue | December 30, 2012 1:05 PM    Report this comment

Part 2 - the stall occurs at the same critical AOA all the time. 1 g or 9 gs. To not discuss aviation in a 3D environment is to pass along bad information and is a disservice to all. It also makes concepts like stalls, more difficult to understand.

I have shared this thread with 6 of my buds, all extremely well steeped in aerodynamics - 1 is an advisor to my new site at Iviation.com and he was Fighter Weapons School CC. 1 a USAF student, retired LTC and F-16/A-10 pilot, 1 a C-130 guy and SQ CC at Shephard inT-6, another GA only backgound but knowledgeable in aerodynamics and finally a guy I mentored when he was a kid now flying F-18s in the Navy and trying out for the Blue Angels. They all agree with me. There is so much wrong info and flak, I started to doubt myself cuz it's been almost 18 years since I taught this stuff

Posted by: David Perdue | December 30, 2012 1:11 PM    Report this comment

"AOA vs stall: Isn't there a big difference in behavior between props and jets in the stall? Most props blow air over the wing and tail, inhibiting stall beyond the published AOA and improving stall recovery".

An AOA on a prop plane (especially a twin) will instantly register a decrease in AOA and an increase in lift reserve when power is applied and the wing/flap section behind the props receives the prop blast. No need to accelerate the entire airplane to pick up airspeed indications.

You can learn a lot from watching your AOA.

Posted by: jim hanson | December 30, 2012 1:11 PM    Report this comment

Part 3 -This is a great discussion because I've had to go back and dig into old material and re-learn some things.

Everyone is in agreement, we can be 60 degrees of bank in 1 g. Again, don't think level turn.

A big point here - You are not Navy pilots. You do not fly like the Navy nor have the same training, equipment or objective as the navy. The navy flies a steeper approach to the deck whose sole objective is to catch a wire to stop, on boat landings. Here is what my F-18 bud who i mentored emailed me back....Keep in mind, their AOA is integrated into the aircraft systems.

I can't speak to the other communities, but the boat guys fly AOA. We do an a/s crosscheck with landing checks, and we practice no hud and standby approaches. In primary we flew constant a/s approaches, but since kingsville, I've done AOA. The hud is our primary flight instrument, so we do a meatball, lineup, AOA scan on the ball. As a side note, your dad said you've got a website up now.

The USAF incorporates the airspeed in crosscheck.

AOA is a great tool/instrument and worthy of praise. I never said otherwise. I did say airspeed is to be in the cross check and i did say that you do not need AOA to be a safe competent pilot in GA aircraft. I stand by that. Obviously, a lot of people are taught wrong/inadequately but relying solely on AOA gauge is not smart.

Posted by: David Perdue | December 30, 2012 1:19 PM    Report this comment

Pt 4 - also, teaching pre-positioning of the stick - bad idea. If you teach that to someone going in to the military, they won't make it because it is not a smart thing. The aircraft needs to be felt and stalls and their characteristics understood. If one gets in the wrong situation and prepositions the yoke hoping the aircraft will respond a certain way and it doesn't, could be in for trouble. Example, you normally fly at 2 - 3000 msl and now your 6-8000 msl. the plane handles differently and the stall speed is higher. Same with weight of an aircraft. and flying different aircraft.a

There's so much flak (pardon the term) it's hard to keep straight on target (again pardon) but suffice it to say, stalls can be no big deal if taught properly.

We, in GA, are not fighter pilots or have the training the military went through, so we need to be careful what techniques and practices can be transferred to GA and what (few) cannot.

I have a saying given to me by my T-37 instructor who previously flew F-15s.

"Just because you have your drivers license, doesn't mean you are ready for the Indy 500"

I say, just because it's legal, doesn't make it safe or smart.

Everyone, fly safer - live longer (TM) and be careful where you get your information and techniques from. It could kill you.

Posted by: David Perdue | December 30, 2012 1:26 PM    Report this comment

When I was doing CFI, mostly PA-28s, I taught stall/spin avoidance by doing a lot of “slow flight”. I had my students fly with the stall warning light continuously ON at an assigned altitude, usually 3000′, in level flight. Yoke for nose attitude and throttle for altitude. When that could be accomplished, the next assignment was to follow a specific ground oriented pattern (eyes out of the cockpit). At LGB, parallel the break-water and do a 180 at the end and track the opposite direction for several orbits, light/buzzer on all the time.

Sometimes, a stall might result. I always found that the student almost instinctively knew what to do for recovery. They had a good feel for the airplane at those speeds, and recovery seemed to provide them confidence that they could handle the airplane. When in doubt, I’d have them do a few intentional stalls out of the same configuration.

Get them up in the burble and stay in control.

Posted by: Edd Weninger | December 30, 2012 1:26 PM    Report this comment

Edd, you are right on the money with what you wrote!

Posted by: David Perdue | December 30, 2012 1:33 PM    Report this comment

I'm surprised at the "pitch-over" at loss of power comments. Just about every plane I've flown, with the exception of the Lake, when the plane is trimmed for Vx or Vy pitches down of its own accord with power loss.

Posted by: Edd Weninger | December 30, 2012 1:49 PM    Report this comment

piling on with Ed: The FAA has been conflicted over the years about slow flight vs minimum controllable airspeed. In the late 80s it was all about MCA and hanging on the prop in the PP PTS. then it became an undefined 'slow flight' and anything less than cruise qualified. IIRC MCA or something like it moved to the commercial PTS.

Now 'maneuvering during slow flight' is back in the current PTS but the steps include: Establishes and maintains an airspeed at which any further increase in angle of attack, increase in load factor, or reduction in power, would result in an immediate stall. Accomplishes coordinated straight-and-level flight, turns, climbs, and descents with landing gear and flap configurations specified by the examiner.

That's MCA in a different color crayon IMHO, and the PP and commercial PTS are identical on the task except the odd limitation for commercial pilots to only take a stall to the buffet while the PP PTS requires a stall break. I suppose there is logic to that, but it eludes me.

There's nothing like a set of foggles to teach finesse, especially during slow flight with turns to headings, climbs and descents, stalls and UA recoveries. It isn't exactly appreciated at first, but I swear that after an hour of that a different pilot steps out than stepped into the plane.

Posted by: Thomas Connor | December 30, 2012 2:02 PM    Report this comment

AOA is OK for the critical task of Navy pilots putting a jet aircraft on a short section of pitching deck--but not of use to GA pilots? Why not?

Why is it OK for Navy pilots to rely SOLELY on AOA, but for Air Force and GA pilots to do the same is "taught wrong"?

Why WOULDN'T incorporating AOA into GA training be beneficial?

"Teaching Stalls" at altitude or an admonition to "avoid stalls" hasn't worked in a hundred years. What IS the answer?

Posted by: jim hanson | December 30, 2012 2:04 PM    Report this comment

Maybe airplanes should have a microswitch on the control stick that sounds the stall horn at stall/stick position. That way the pilot could go in and out of stall almost instantly with simple rapid stick movements ( and learn to react) This would permit the pilot to use heads up while looking outside rather than attempting to stare at some AOA indicator. Maybe this is already suggested in STICK and RUDDER. I will look and see.

Posted by: Bill Berson | December 30, 2012 2:29 PM    Report this comment

What's the history behind AOA indicators in heavy iron but none in GA? It would be interesting to know the story and rationale.

Posted by: Thomas Connor | December 30, 2012 2:47 PM    Report this comment

With regard to the relative “risk” difference between stalls and mid-airs, I fear mid-airs more than stalls. In more than 50 years of flying, I have three stark recollections of VERY near- misses and only one incident of a stall condition doing something unexpected (Cessna 336 balked landing simulation with a turn to the right, spun over-the-top to the left and left us inverted with ~45 degree nose down pitch).

With regard to near-misses, all three were VERY close in VFR conditions in a busy traffic environment with lots of eyes to see-and-avoid. Since flying with TCAS in my plane since 2005, I’ve become more convinced that see-and-avoid is not serious risk mitigation. Too many blind spots from the cockpit.

Been flying into the busy LA Basin since 1962. Now with TCAS pointing out targets, seasoned eye-glassed pilots can only spot about half of them within a 6 mile radius.

Posted by: Edd Weninger | December 30, 2012 2:48 PM    Report this comment

Now with TCAS pointing out targets, seasoned eye-glassed pilots can only spot about half of them within a 6 mile radius.

I hear this a lot. When we got TIS in our airplane, the statement that "you have no idea how much traffic is out there that you don't see" made sense.

But traffic system advocates--I'm agnostic--don't often offer the rejoinder, which is that you have no idea how much traffic is out there that you don't see that's no factor.

See and avoid works. It's just not perfect. If it didn't work, you'd see a mid-air every day and you don't. You don't even see one a week or even one a month. The traffic system-equipped light aircraft fleet is not large--under 10 percent I'd guess.

Statistically, it may be getting to the point where these system are having an effect on the numbers, even though that's not evident in the data. Yet.

Not to say midairs aren't a demon. They are just a small one. I fear midairs more than stalls, too, but given the data, the fear is somewhat irrational.

Posted by: Paul Bertorelli | December 30, 2012 3:10 PM    Report this comment

"What's the history behind AOA indicators in heavy iron but none in GA? It would be interesting to know the story and rationale."

The FAA formerly required AOAs to be certified and STCd--costing tens of thousands of dollars. Even the "stall warner" type stagnation point system offered by Safe Flight Instrument cost a lot of money.

FAA changed its mind and has recently allowed AOA and Lift Reserve Indicators to be installed as "supplementary information" (much like non-certified GPS systems) without an STC. Costs now range from about $700 to $1500, depending on the indicator. As Paul Mulwitz points out, you can even build your own.

It's analogous to "Heavy Iron" avionics--a flight management system might cost well north of $100,000. An approved panel-mounted GPS will do almost everything the FMS will do for well under $20,000. A Garmin 696 may give even MORE information, but is not "approved". That hasn't stopped pilots from buying and using the cheaper units in the hundreds of thousands.

Our local radio shop offered this advice when I asked if we could add weather to the Garmin 530 on our Sabreliner--"yes, but you won't like it--it's expensive and difficult for Garmin to change. Buy a Garmin 696 and have the best of both worlds."

Posted by: jim hanson | December 30, 2012 3:22 PM    Report this comment

I’ve had the bad luck to see four people die in two stall related accidents. The first was a 2-place glider on landing approach at Cedar City shortly after I landed and was unloading my plane. The approach was high and into a 10-15 Kt headwind. Pilot started a left 360. About 270 around the turn steepened, the nose fell through and they went straight in. I thought the pilot became concerned when low and being blown away from the runway in the breeze, thought he had plenty of airspeed because of the visual impression of groundspeed, and yanked it around.

The second was a Bonanza turning base-to-final at Big Bear. A cross wind blew him past the turn to final. He steepened his turn, the nose fell through and went straight in. I did not hear a change in power. I believe he was also duped by outside visual clues that were incorrect. The summer density altitude meant the groundspeed was higher when he was low to the ground.

Not sure what would have worked in either situation. Both occurred very quickly, seconds or so it seems. One moment there was a flying aircraft, a moment later there was a sickening CRUNCH. If you’ve heard it you’ll never forget it.

Posted by: Edd Weninger | December 30, 2012 3:24 PM    Report this comment

Paul B. I am willing to guess you are not much of a gambler. You seem to think if the odds are low that means the (bad) event won't happen. This is simply wrong thinking.

If you were really convinced the low odds of a mid-air collision protects you from having one of these life ending events you wouldn't ever look out the windshield to avoid traffic. After all, the odds are so low it just couldn't happen to you . . .

I have had a lot of incidents where I got much too close to other airplanes. It was always in the airport traffic area, and usually due to a misunderstanding of my position or the other guy's position while we were talking to each other on the radio.

I am really ready for full ADS-B and look forward to the traffic information much more than the weather that seems to be drawing a lot of business now. Alas, there is no single solution for this new technology yet. Perhaps a couple more years will make it practical for someone like me to buy one product that gives me all three components of an aircraft ADS-B system: In, out, and graphic display.

Posted by: Paul Mulwitz | December 30, 2012 3:50 PM    Report this comment

Keep in mind that Air France 447 had a simulator-trained crew, computers, AoA instruments, and 30000+ feet and still managed to stall all the way to 0 MSL. It's not the stall, it's the impact with the surface that hurts.

Asking why stalls cause more accidents is like asking why distracted driving is the number one cause of auto accidents. Simple--there's a human involved. And no amount of stall training as it is currently practiced is going to fix this. As AF 447 shows, it's not the stall, it's the impact that kills, and the unfortunate reality is that the conditions that are most likely to induce unexpected stalls occur close to the surface: squirrelly winds, maneuvering, low speeds, ground-speed visual effects, and human errors in judgment (bad CG, no fuel, high DA, etc.) And the condition that causes the actual accident (the ground) is right there too. No amount of slow-flight or stall training at 5000' AGL is going to help when you depart Denver on a hot day in an overloaded Bonanza and feel the all-too-human need to avoid the street lights.

Practice in a life-like simulator is probably the best way to train for realistic quick-reaction-required stall scenarios or to learn the consequences of bad decisions (and survive), but the sad reality is that when that sort of computing power arrives the computers will probably already be flying the plane for us.

Posted by: Robert Johnson | December 30, 2012 6:52 PM    Report this comment

"You seem to think if the odds are low that means the (bad) event won't happen. This is simply wrong thinking."

That's absurd on its face, Paul. As I noted in the original text, mid-airs represent nearly the smallest demonstrated risk in aviation, yet some pilots are willing to spend thousands to reduce it because of the demon factor. Meanwhile, much larger risks, which they tend not to prepare for, are several times more likely to kill them.

Try this thought experiment: Of the 195,000 airplanes in the GA fleet, about 20,000 have traffic systems. Equipping the remainder would cost $1.7B and since no technology is perfect, it might cut midairs by 80 percent, say from six a year to one. If you were in charge of spending, would you do that?

As for see and avoid, it's silly to say you wouldn't look out the window because you believe the probability of a mid-air is low. It's low because you *are* looking out the window. See and avoid works. It's just not foolproof. If it didn't work, we would have dozens of midairs each year and we don't.

My view is that to understand risk, you have to (a) sort it from smallest to largest based on demonstrated data and (b) avoid the mistake of thinking the large risk factors don't apply to you. In other words, "I'm stall proof." I think many of us assume certain kinds accidents will never happen to us and many of those people end up in smoking holes. I know a couple of them.

Posted by: Paul Bertorelli | December 31, 2012 6:46 AM    Report this comment

>Not sure what would have worked in either situation.<

What would have worked would have been not steepening the turn beyond a pre-determined bank angle for the situation. For the glider, it might have meant landing off airport. For the Bonanza, a go-around. That's basic airmanship.

Posted by: Malcolm Ruthven | December 31, 2012 7:04 AM    Report this comment

Paul B. Let me say a couple of things which might help this impasse.

First, I am a better gambler than pilot. I go to Las Vegas several times a year to play poker at the best card rooms in the world and nearly always come out ahead.

That said I understand that a low probability is not something that won't happen. It is something that doesn't happen very often. It still happens. Even the state lotteries usually find a winner. The problem (as you almost pointed out) is the payoff is not big enough to pay for the risk.

Now for the stall vs. mid-air issue. As a reasonably well trained pilot I KNOW I will never get into a fatal stall. I stay aware of the risk and take sufficient preventive measures to insure it doesn't happen to me. I can't do that with mid-air collisions because I can only control half the risk. The part the other pilot must do is beyond my control. I don't like that. I would rather be able to see all traffic - even the planes that are sneaking up in my blind spots. ADS-B should provide that without any extra cost since it will be required soon anyway.

Posted by: Paul Mulwitz | December 31, 2012 7:10 AM    Report this comment

"And no amount of stall training as it is currently practiced is going to fix this. "

Sadly, you may be right. But there's a test of this underway. A couple, actually. When Cirrus introduced airplanes with BRS, it was hoped that this system would make certain kinds of accidents more survivable, stalls and spins among them.

It hasn't because pilots haven't learned to deploy the system. There are as many as 30 Cirrus fatals that wouldn't have been fatals if BRS had been deployed. So the Cirrus community has upped the training game to include scenario-based simulator deployment decisionmaking, just as the military did in the early days of ejection seats. In five years, we may know if it's working if enough pilots are exposed to it.

For now, we do know this: Despite Cirrus' laudable effort with the parachute and dual-incidence wing, its rate of stall-involved accidents is among the highest in GA. This makes me a little skeptical of technological panaceas like AOA indicators. Good idea for sure, but our GA culture is big on adopting shiny objects but not so big on training integration to make them effective.

Posted by: Paul Bertorelli | December 31, 2012 7:13 AM    Report this comment

I was fortunate enough to find a copy of Stick and Rudder in the school library when I was 13. I had to read it a few times to really get it at that age. For those who haven't read that classic, it explains angle of attack as it relates to pilots, not engineers.

Fast forward to about 10 years ago, when this Bonanza 36 pilot made a series of mistakes with a heavy load on a hot day from a short runway (unintentionally didn't use all of it for takeoff, the big mistake) with high hills in the departure path. I wound up headed into those hills, too low, with the stall warner starting to beep. I'm fortunate to be able to say that my basic airmanship took over as I very consciously reduced the AOA gently, then started a gentle right turn toward lower terrain. If I hadn't been grounded in basic AOA airmanship, my prior mistakes would have killed all five of us.

Posted by: Malcolm Ruthven | December 31, 2012 7:22 AM    Report this comment

Paul B. - I agree with you on the shiny object issue.

The Cirrus experience, in my opinion, is more about the marketing ideas used to sell those very expensive airplanes than anything else. They marketed toward non-pilots saying the design with its parachute was so safe the pilot didn't have to be very skilled or experienced to do well with this very high performance design. History has proven that claim to be wrong.

As I have been saying, I feel differently about the traffic display with ADS-B. This is not so much a shiny object as a real improvement in surveillance. It gives fully trained and competent pilots an additional way to see traffic.

Posted by: Paul Mulwitz | December 31, 2012 7:30 AM    Report this comment

"First, I am a better gambler than pilot. "

It's odd to me that you've used the gamble analogy twice. I don't apply that to aviation in any way, for I believe there is a difference between risk taking and gambling. I don't view aviation, or skydiving or motorcycling as games of probability where a certain outcome will occur a certain number of times over the run of the game. I have a vote in the outcome.

In aviation, you do certain things to actively reduce risk. But to do those things, you must actively understand the nature of the risk you are confronting and I submit that most pilots do not..

To put a probability number on it using exposure units we all accept--one flight hour--a midair risk of .02 is one occurrence per 3.6 million hours. Round it down a little and call it .3 chance in a million. Pretty low. That's the world as it is, by the way, with a combination of see and avoid and traffic systems. Let's say a traffic system cuts that risk in half. Thus you've spent $10,000 to reduce an already microscopic risk, but what have you done to mitigate the engine-failure risk, which is four times greater? Or the loss of control risk, which is five times greater? These are global risks. by the way. If you fly the Hudson corridor or LA's zip-lip VFR corridor, maybe it's higher. And is it an illusion to think you have those other risks covered because you think you control them?

Posted by: Paul Bertorelli | December 31, 2012 8:22 AM    Report this comment

None of this is to suggest that buying a traffic system is irrational. I bought one, too. This is merely a footnote to say when you cast your vote for risk mitigation investments, isn't it good to understand the nature of the risk first? And if you over inflate one demon, as we all do, which larger one are you actively ignoring?

Posted by: Paul Bertorelli | December 31, 2012 8:23 AM    Report this comment

On risk, it's no mystery that pilots are more afraid of things out of their control than in within. The mystery is that it isn't expected. The bigger mystery is government and business management not understanding this phenomenon.

On the Cirrus wing/stall issue. I have always felt there was something wrong with the original design. Flying one didn't feel right, and I didn't like the way the plane's CG felt to be in the wrong spot. I do believe the improvements may have fixed the wing issue. Of course, the pilot world is full of guys who, understandably, call BS on anything you can't prove with numbers. Also, the idea Cirrus fixed something they never admitted sounds like a nutty conspiracy theory, but I think the results will eventually show in the data.

Lastly, if stalls are the big killer, then why aren't Diamonds safer? Oh wait...

Maybe more schools and pilots should dump Cessna like a can into a blue bucket.

Posted by: Eric Warren | December 31, 2012 8:38 AM    Report this comment

Paul B.

I try not to ignore any risks.

First you say you don't see aviation as a game of probability and then you repeatedly quote probabilities based on accident rates. Which one is it?

Your examples of traffic situations are a long way from the worst ones. I think the worst are two situations that you probably never face. The first is skirting around Class B and Class C airspace. This is done by a lot of VFR pilots to avoid talking on the radio to ATC. It creates a very high traffic density right at the margin of those airspaces. It is even worse, actually a lot worse, when you fly to an event that attracts a lot of planes. This could be anything from a pancake breakfast to a local annual fly-in to AirVenture or Sun-n-Fun. The traffic density at these events is nothing short of incredible. Even with special procedures such as you find at major fly-ins I have had "Near miss" events that got my attention.

I strongly suspect that you are on the ground with your keyboard and microphone while the rest of us are dodging aluminum clouds.

Posted by: Paul Mulwitz | December 31, 2012 8:42 AM    Report this comment

"First you say you don't see aviation as a game of probability and then you repeatedly quote probabilities based on accident rates. Which one is it?"

What it is, Paul, is using actual data to decide where to put the risk mitigation effort. Your gambling analogy makes flying sound like poker, in which you have far less control of the outcome.

"I strongly suspect that you are on the ground with your keyboard while the rest of are dodging aluminum clouds."

Yeah, that's it Paul. Last month I was at Vero Beach threading a Piper Matrix through the clouds of Flight Safety students who can hardly speak English. And the month before that, it was a TBM in the Miami Class B at 200 knots. I realize these aren't as challenging as flying a Zodiac LSA, but I do try to keep up. I hope you'll forgive my inadequacies.

Posted by: Paul Bertorelli | December 31, 2012 8:59 AM    Report this comment

OK, I went a bit too far. I apologize.

The problem with current traffic systems is they are radar based. That means they only see most of the traffic rather than all of it. The same kind of problem applies to depending on ATC to prevent collisions. I remember reading about a mid-air in the LA area that occurred between two IFR flights. I'm hopeful ADS-B will fix those issues along with being available at a much lower price than the $10,000 you mentioned for current collision avoidance systems.

It seems odd that the Zodiac XL experience includes about 10 structure failures (which are very rare in the general GA experience) and one mid-air collision -- all in the last few years. Perhaps flying one of these unlucky airplanes makes me a lot more conscious of the more unusual risks in aviation.

Perhaps we will just have to disagree on the probability issue. I think you are using accident statistics to say low rate accidents are not worth much worry because they are unlikely to happen to me. The same kind of thinking applies to your comments that stall accidents are common in the entire population so I should worry about them happening to me. Indeed I do worry about stalls so I devote a lot of attention to avoiding them when low and slow. I also worry about collisions because they are real possibilities that I cannot completely control. I am all for any solution that gives me significantly more control over them.

Posted by: Paul Mulwitz | December 31, 2012 9:13 AM    Report this comment

A friend of mine died in a gruesome stall/spin accident at Oshkosh in 2001. I knew him well enough to know that he would have considered himself in the stall-proof population.

The lesson I draw from this is that hubris can lead to dangerously false assumptions, so for me personally, I like to think I'm susceptible to any of the accident categories posted above and I train and plan accordingly.

YMMV.

Posted by: Paul Bertorelli | December 31, 2012 9:31 AM    Report this comment

Klapmeier survived a midair and mandated all Cirrus have a parachute for midairs.But the risk is low, perhaps the money could be spent more wisely? ADS-B won't help much in VFR airspace where it is not mandated. Radar already provides separation in class A, B, C. So what will change with AD-B mandate in 2020?

Posted by: Bill Berson | December 31, 2012 10:49 AM    Report this comment

Radar only works on metal airplanes or ones with transponders turned on. That leaves a fair amount of invisible planes. This shouldn't be a problem in Class A or B air space, but C allows planes with no transponder and has no mode C veil.

It is true the current plan is to require ADS-B out only in certain areas but I expect most people to have it in all areas. It also works everywhere while radar is only available in a small number of high density areas.

Posted by: Paul Mulwitz | December 31, 2012 11:41 AM    Report this comment

Robert Johnson--"Practice in a life-like simulator is probably the best way to train for realistic quick-reaction-required stall scenarios or to learn the consequences of bad decisions (and survive), but the sad reality is that when that sort of computing power arrives the computers will probably already be flying the plane for us."

The simulators already exist. There are Cirrus simulators in Minneapolis, Las Vegas, and Atlanta that have an actual Cirrus cockpit, excellent visuals, sound, and six degrees of motion--just like the airlines and the bizjets. Like most high-fidelity simulators, it costs about the same as the actual aircraft--almost $600,000. (Note to Paul B--flying one would be an excellent article!)

I've flown it--done approach to land stalls at low altitude, engine failures on takeoff, and icing encounters. All are realistic enough to cause your heart rate to skyrocket. The problem is--they rent for $195 an hour. That's not bad, considering how much you can do in an hour, and not much more than an hour of dual in a training airplane. There's no question that the experience is far more meaningful than "practicing" at altitude--something that most pilots don't transfer to an actual emergency.

How many pilots would pay $195 an hour? Not many--but if the FAA (or the insurance companies) gave credit for the experience (either towards a rating or for your insurance) more people might try it.

Posted by: jim hanson | December 31, 2012 12:54 PM    Report this comment

Nearly 70 years ago, Wolfgang Langewiesche laid it all out in pilot-understandable terms in "Stick & Rudder." Yet, to this day, there are people out there who, out of misconceived ideas of "safety," try to reduce a somewhat complicated story to simple rules that capture only parts of the whole truth, or propose simple remedies that neglect all the subtle, yet important "Yes...buts!" encountered in flying. I hope that someday we will have a fully convincing stall/spin simulator, complete with ground-reference and comm distractions, energy management conundrums, and other common surprises, that would lead students to develop a correct mental assessment of how the airplane was doing, and produce the right instinctive reactions. Then you wouldn't see people skidding turns while trying not to bank "too much" in the pattern, and other idiocies. Valuable as an AOA indicator might be, I don't think it alone would do it. What's necessary is live or realistically-simulated experience at or close to the edge, combined with input from an aggressive and competent instructor. Once a complete mental model of how the airplane flies is securely in place, the incidence of stall/spin accidents should fall off dramatically!

Posted by: Nicholas Reinhardt | December 31, 2012 1:23 PM    Report this comment

" I hope that someday we will have a fully convincing stall/spin simulator, complete with ground-reference and comm distractions, energy management conundrums, and other common surprises, that would lead students to develop a correct mental assessment of how the airplane was doing, and produce the right instinctive reactions"

Here's a link. It does all that you ask. www.simtrain.net/

Correction on the last posting--I did a magazine article on the simulator--and quoted a cost of $600,000. The sim "only" cost $450,000--the rest was for the office and other equipment. Still a bargain at $195 an hour. When watching the short video, compare the outside horizon, EFIS horizon, and standby horizon for fidelity.

The article I did was on "What VFR pilots can learn from a good flight simulator." I've seen the inside of clouds before--but how realistic can the sim be? VERY realistic--approach to landing stalls, engine failure on takeoff with a turnback, icing encounter (with a parachute pull), wake turbulence encounter, and even some loops and rolls thrown in--all in an hour.

Posted by: jim hanson | December 31, 2012 2:04 PM    Report this comment

I would love to see ADS-B become as ubiquitous and as inexpensive as GPS currently is. I suspect it would decrease the already-low rate of mid-air collisions, much as it seems GPS has decreased the number of "Help--I'm Lost!" I-Learned-About-Flying-From-That articles I see in trade publications.

However, I think Malcolm really got the gist of what I was trying to say. I too read Stick and Rudder as a teenager and developed an intuitive understanding of AoA at an early age. Notice that stall training did not help Malcolm, as he never stalled. Also note that an AoA gauge wasn't needed, and probably wouldn't have helped, or been used. It was an intuitive understanding of how a plane flies coupled with a calm application of airmanship that saved his day. And luck.

Sadly, correct, calm intuition is hard to teach, and even harder to practice on a daily basis. Intuitively, the general public believes the higher you fly the greater the danger; pilots know better. That's why I disagree slightly with this article. Paul B. writes that an accident starting with an engine-out followed by a stall to the ground should be attributed to the stall. I disagree. It should be attributed to proximity to the ground. Conditions are different close to the ground, and more importantly, many pilots react and behave differently close to the ground. The auto industry attacks this human element via airbags and the airlines via computers; I don't see any such tech solution for GA any time soon.

Posted by: Robert Johnson | December 31, 2012 2:44 PM    Report this comment

I think Jim Hanson has pointed out the best currently available technological solution to the problem of low-and-slow training. At the other end of the scale, there's the old J3 Cub approach, which also gives you a feel for life down low-and-slow. The problem is that neither of these are readily available to most GA pilots training today.

Posted by: Robert Johnson | December 31, 2012 2:53 PM    Report this comment

If you can't find a Champ or a Cub, there IS glider training available throughout most of the country. There's a reason that most of the East Bloc countries use gliders for initial training--as well as the USAF Academy. It teaches control, coordination, and develops a relationship with the AOA of the wing without confusing pilots with the engine. Glider pilots live on the edge of a stall while thermalling tightly--with their attention diverted outside. They don't have a stall warner--they simply unload the wing by relaxing a bit of back pressure and continue without even thinking about it--and isn't that the outcome we are trying to promote?

Glider pilots obviously learn energy management. Fear of the ground? Every glider pilot trains for a rope break at altitudes as low as 200'--and the performance of a 180 degree turn IS an option on most gliders (depending on towplane performance).

Glider flying will make a better power pilot out of you--and besides, it's FUN!

Posted by: jim hanson | December 31, 2012 4:19 PM    Report this comment

Earned pvt in 66, lots of stall training/practice in ch-140. Got cml 68, lots of slow flight practice and stalls from every configuration as well as simulated pwer loss, much of the time down to within couple hundret ft over empty fields. Also had to do 3 turn spin recovery, something they dont do now. Honestly, scared the crap out of me. I dropped out a few months after for periaod of 35 yrs. When I started back, all that training and exerience brought me back up to speed very quickly. Now adays I always make sure ball is where it should be on base to final turn. Always, always

Posted by: charles heathco | December 31, 2012 4:58 PM    Report this comment

For every glider and power plane I have flown when a stall is approached slowly, the stick has always been in the same position, regardless of the angle of bank. I believe this to be true as long as the CofG does not change. Power settings can change things especially if they are away from centreline or affect elevator airflow. A real AOA would be better though. Doubters could check out the stick position on their own planes. Things should change though if a back seat is filled.

Posted by: Ray St-Laurent | December 31, 2012 5:33 PM    Report this comment

I was going to write a long-winded piece about basic skills vs. glass, but I think that everyone else already has. That said, I fly gliders and tugs in/out of a small (but on the charts) airport, and I guarantee you, counting the rivets on a C-130, in the pattern at 700', as you turn base, in a 20:1 ship, will make you wonder about collision (or near collision) avoidance.

I'm not arguing for more computers or regulations, but just trying to explain perceptions.

Posted by: Merl Raisbeck | December 31, 2012 5:44 PM    Report this comment

As an old glider pilot, the prevalence of “lost control while turning back to the field” and its variations always puzzled me. Until recently. On downwind killed the engine for the first power off circuit pattern in my Virus. I was surprised how much the nose had to drop to maintain airspeed. I realized most power pilots have approximately zero time doing steep turns with the engine idle or power off. In a stress event like power failure on TO or overshoot base to final, concentration can lapse and people revert to what they are most familiar. In this case the nose in a higher, power on, attitude. Good recipe for stall/spins.

Posted by: Ray St-Laurent | December 31, 2012 5:50 PM    Report this comment

Regarding the stick position when approaching a stall--do you suppose it might have something to do with the fact that when the TAIL no longer produces downward pressure, the nose falls through and the aircraft recovers?

Just asking--I'm not sure whether you are noticing CAUSE or EFFECT. At any given similar CG, wouldn't the tail always stall at the same negative AOA (or speed) AFTER the wing stalls, causing the nose to drop?

Langewiesch, in his 1944 book, listed the negative effects of restricted control travel--limited CG, possibility of a spin anyway without restricting the ailerons and rudder--difference in elevator control power on and off. He mentioned being able to accomplish that with "10 cents worth of wire." The failure of the Ercoupe in the marketplace argues against limited control--I don't think that's what pilots want.

Posted by: jim hanson | December 31, 2012 6:07 PM    Report this comment

I like to reread Stick and rudder once a year. He explains how pilots stall in turns. And he recommends more top rudder than aileron when exiting the turn. I try to remember this: don't use the rudder to " force" the turn ( skiding). But do use the rudder to lift the wing and end the turn without spinning ( slight slip).

Posted by: Bill Berson | December 31, 2012 6:19 PM    Report this comment

When the wing stalls and the tail does not the nose will drop so you can practise stall/spin recovery. If the tail stalls first, tail drops, wing AOA increases, you get to practise screaming out of control.

The ercoupe had no rudder pedals.. A friend had an ercoupe and took it as a challenge that it was unspinnable. He tried and got close before he realized he would never be able to get out of a spin with no separate rudder control.

Also what would happen if frost was on the wing changing the AOA of stall? I think it is better for aircraft/pilots to have easy approaching stall recognition and have an quick/easy recoveries.

Posted by: Ray St-Laurent | January 1, 2013 9:04 AM    Report this comment

>If the tail stalls first, tail drops<

In a conventional aircraft (non-canard,etc), the center of gravity is in front of the center of lift of the wing and the tail/elevator exerts a downward force to counterbalance that. If the aerodynamic action of the tail/elevator goes away, the tail would rise and the nose would drop.

Posted by: Malcolm Ruthven | January 1, 2013 10:42 AM    Report this comment

Oops. Malcom is right.

Posted by: Ray St-Laurent | January 1, 2013 10:47 AM    Report this comment

Glider flying is great for teaching basic stick and rudder skills. Love flying them. I've also had an engine failure during climbout in a Beech Skipper and, like, Ray St-Laurent, was shocked at how fast and how hard I had to push the nose down--I could have sworn I was pushing 40 degrees over, but I'm sure that was just my shocked impression.

My argument with this article is the notion the more stall/spin training at 5000' AGL is going to reduce the stall-related accident rate significantly. I don't buy it. No spin-recovery skill is going to help once you depart controlled flight in the base-to-final turn. Like I said, it's the ground that kills, and you'll be there in 1/2 a turn. The training is fine, but at 500' AGL understanding what's happening BEFORE the break is more important.

Here's a more realistic scenario: you've been holding in your Bonanza at Ripon for an hour. You're cleared down the tracks. Gear and flaps are down, power is up, you're following a Zenith 701 at 70kts, 1000' AGL. It's gusty--the stall warning horn is intermittently blaring. Kids and camping gear in the back. The wife in the right seat wants a restroom bad. Your presentation starts in 30 minutes. Planes everywhere. 10000 pilots lined up judging your approach. The 701 flies slower and turns final. You're too close to him. What do you do?

When you can realistically train for scenarios like that, THEN the stall-spin accident rate will drop significantly.

Posted by: Robert Johnson | January 1, 2013 3:04 PM    Report this comment

In our search for the latest in shiny objects to avoid smoking holes I have not seen mention of the yaw string. If it's good for the U2 maybe we could consider it too. en.wikipedia.org/wiki/Yaw_string

Posted by: Thomas Connor | January 1, 2013 4:00 PM    Report this comment

Robert, if you can't comfortably fly your Bonanza at 60 Kts then I must question your judgement on putting your family in the plane and flying to OSH. Even in that environment you can do a go-around. You can also do what is part of the program at Arlington and land on a different point on the runway than the guy in front of you.

One last point: I believe the procedures for AirVenture include dividing aircraft based on performance before moving into the pattern. You could always limit your Bonanza to the high performance group - even though it is the pilot and not the plane that needs to go fast in the pattern.

You didn't say how you got so close to the 701 in the first place. If you started on downwind then you simply turned base too close to it. That could happen at any airport in normal traffic. Perhaps just some ordinary flight at uncontrolled but busy airports would be a good starting point to train for the OSH experience?

Posted by: Paul Mulwitz | January 1, 2013 4:16 PM    Report this comment

Airplane - RV8

Flew 4 stalls - power off, mid power-on, full power-on, and accel. Luckily dynon provides an auto-pilot servo position readout in the autopilot status page. I noted the stick position during each stall and translated this to - Inches From Neutral (IFN) elevator. My pitch servo outputs 202 step units through a 12" stick range (measured at the thumb/index finger grip point). 108 steps is neutral stick.

Results: steps IFN (aft) Power Off 50 3.45 mid power 62 2.73 full power 68 2.38 accel 41 3.98

Stick position cannot reliably be used as a defacto stall warning as it will change with CG, GW, DA, Flaps, power, what you had for breakfast, etc.. Of course we all know this but here is the proof.

Posted by: Ken Kopp | January 1, 2013 4:26 PM    Report this comment

At CAP search exercises we'd bring our ride to a sar base and end up doing staff work so others took our ride out for practice SAR. The fleet spanning 30 years of the C-182 festooned with antennas, blisters and pods hung willy nilly, not to mention different engines, fuel tankage and empty weights, so each flew differently.

Some air bosses wanted crews to do controlability checks and abort if there were problems we'd rather not learn about in a mountain valley. The checks were simple: Trim it for hands off flight. Steep turns left and right, then slow to MCA clean and dirty, power off, power on and accelerated stalls to the buffet. Note IAS for when the stall horn came on and the stalls. It's amazing how we become accustomed to some idiosyncrasy that is apparent to a new pilot. The advise after a balked landing or bird strike was identical: Do a controlability check.

We also compared actual to book climb rate and level best-power cruise IAS/TAS to get some idea of power output along with in-flight mag checks. If high DA or load couldn't explain a lower than book IAS/TAS the crew stayed out of challenging terrain.

Posted by: Thomas Connor | January 1, 2013 4:40 PM    Report this comment

Ken, Thank you for that. Very accurate results and what I was hoping for. Stall stick position does change "slightly" with the changes you mention (DA is not one of the, though). 202 steps in 12 inches equals approximately 0.06" per step. Your largest change was 2.38 to 3.45 steps which equals 1.07 steps or roughly 0.065" of a difference in stick movement over your power range. Similar changes are made when CG is different and with flaps etc. add them all up together and you would be lucky to have a difference in stick position of maybe a quarter inch in 12 inches of travel. My contention is this is for all intents and purposes for the pilot who is pulling the stick, the exact same position. If he notices a difference of 6 thou' or a quarter inch then he has a very well calibrated arm!

Paul B. you said we train pilots to notice power, pitch attitude and airspeed as signs of an impending stall. How hard would it be to simply add in one more at the same time for pilots to take notice (not by looking but by arm/hand position) of stick position? The other three ONLY work for straight and level flight. Stick position works for EVERY stall with perhaps a few differences as Jim has said with thrust line. But even then individual aircraft exceptions could be taught to those people as we do for twins, turboprops and jets. Just saying if we do the same thing and expect a different outcome then we are probably not going to change much... Thanks Ken for the figures.

Posted by: Dave Jardine | January 1, 2013 4:51 PM    Report this comment

Sorry measurement was 60 thou, not 6 thou. My apologies.

Posted by: Dave Jardine | January 1, 2013 4:52 PM    Report this comment

Paul M, I think you misread Roberts post. He is positing a training scenario, and you come off like you are attacking his skill set. Watch out for phrases like "if you can't ..." Saying "one" instead of "you" sounds too formal, but avoids misunderstandings.

Posted by: Eric Warren | January 1, 2013 5:11 PM    Report this comment

Dave, I thought we already discussed what a bad idea stick position is? I discussed it above and so did Ken. We pointed the fallacy of the idea and why it's wrong and could get people killed.

Posted by: David Perdue | January 1, 2013 5:13 PM    Report this comment

Dave J: Is the 'stall stick' thing related to trim speed?

And don't almost all jets with pylon mounted engines slung under or over the wings also have a thrust line different from centerline?

Posted by: Thomas Connor | January 1, 2013 5:16 PM    Report this comment

Eric - I must have completely misunderstood Robert's post. I thought he was talking about his experience.

I have a lot of empathy for people facing unusual situations because of the incredibly high traffic density at major fly-ins. Of course, I think those situations are not the place to learn how to avoid a stall in the traffic pattern.

I didn't mean to attack anyone about their skills. I did want to point out that a place like AirVenture is a high stress situation and some planning ahead and top notch stick and rudder skills are a good way to prepare. Even then you are likely to find new situations that you never anticipated. That is the time when the old solutions still work just fine. A go-around is always in order.

One last thought on the OSH situation. Anyone who tries to fly into AirVenture with only a half hour or even hour and a half (with no holding at Ripon) before a scheduled appearance is guilty of poor planning. Add to that an apparent inability to slow fly his plane and load it up with a wife who needs a rest room and some screaming kids and you are putting yourself into a real bind. All of those problems could be avoided with some planning and a looser schedule. A stop at a nearby airport for the rest room and some food for the kids along with a half day schedule allowance for arriving and parking at OSH seems in order.

Posted by: Paul Mulwitz | January 1, 2013 6:16 PM    Report this comment

"Paul B. you said we train pilots to notice power, pitch attitude and airspeed as signs of an impending stall."

Actually, no. What I was decrying is that stall training is, in my view, too wedded to airspeed and not enough to understanding angle of attack. I've always felt this, but it was driven home when I started to instruct in the Cub, where there are no useful airspeed indications and no one looks at them anyway.

That sort of flying the wing and observed pitch attitude has real value in sensing when you're getting close to a situation where a stall is possible or likely. It's just not the only cue.

The scenario Robert Johnson cited above is, in a way, putting the horse before the cart. The vast majority of these stall accidents are nothing so demanding as what's described. Before we get to that point, we need to get fewer people crumping in just ordinary base-to-final turns or hell, just in taking off. I'm not kidding. That's where a lot of the carnage is.

Posted by: Paul Bertorelli | January 1, 2013 7:06 PM    Report this comment

David - that delta is 1.07" not 1.07 steps. The change in steps was 18 for that stall comparison. Considering the trim band for the RV-8 from stall to Vno is from 50 to 120 steps or roughly 4.1" (12" range of travel is not used by the pilot in flight) a stick position change between stalls of 1.07" is 26% of the normal operating range the pilot is accustomed to. Qualitatively this is very easily discernible as a significant variation in stick position for various stall configurations again showing that stick position is NOT an acceptable measure for stall prediction...period.

With so many variable affecting stick position it is absurd to suggest its use to prevent or determine stall.

Anyway, I only posted because I read the article and saw the bad info being posted and wanted to provide some real data rather than just ranting. You get what you paid for it.

Fly Safe (don't look at the stick!)

Ken

Developmental/Experimental Test Pilot US Naval Aviator (27 years) US Naval Test Pilot School Grad MS Aero BS Control Systems

Posted by: Ken Kopp | January 1, 2013 8:31 PM    Report this comment

Paul Mulwitz, you stated:

"I would rather be able to see all traffic - even the planes that are sneaking up in my blind spots. ADS-B should provide that without any extra cost since it will be required soon anyway."

The ADS-B mandate is only for Out (aircraft transmission) functionality. There is no current requirement to have the ability to receive and ADS-B information.

Since the airspace requirement for ADS-B Out is very closely the same as for transponders, expect many people to not equip and avoid the few places that require ADS-B Out. Plus if you can get into Class C with notification, that helps.

Personally, I think that this ADS-B Out mandate could lead to increased mid-air rates.

Posted by: Ron Lee | January 1, 2013 8:55 PM    Report this comment

Yes, the stick position is not a good way to avoid stall because as Ken found, it changes with power, CG, etc. But also pilots can't feel the stick positions anyway. All this is explained in Wolfgangs book Stick and Rudder. Perhaps some computer could correct for stick position changes. This way the pilot could at least get instant input with micro stick movements. Watching AOA instead of looking forward is hardly optimal as well. I think some major effort needs to address this topic, or nothing will change.

Posted by: Bill Berson | January 1, 2013 8:57 PM    Report this comment

Ron, what you said is true, but I don't agree with your analysis. ADS-B out is not yet available (at least complete systems are not available) but ADS-B in is selling like hotcakes. Many pilots are happy to pay for the receiver to get free weather information along with things like TFRs. So while ADS-B out is the only part required it seems likely many people (including me) will have both the out and in functions when it is easy to buy a complete package.

I don't understand your comment about "get into Class C with notification". Anyone can enter class C airspace if they have a radio. A transponder is nice and most people I know have one of those too.

Posted by: Paul Mulwitz | January 1, 2013 10:02 PM    Report this comment

Thanks for getting the data Ken. If we consider a stall while turning to final as a major killer, the data point of interest is the stick position while for different angles of bank. I have seen a nil change.

Regarding flaps, I have not noticed much difference in poaition for 'normal' flap settings. Exceptions I have seen were in large span flapped gliders such as an HP18 that went to 90 degree flaps. Cruise and soaring settings had similar positions. Landing flap angles beyond 30 degrees required a much further forward stick.

Posted by: Ray St-Laurent | January 1, 2013 10:57 PM    Report this comment

>If we consider a stall while turning to final as a major killer, the data point of interest is the stick position while for different angles of bank.<

I just don't see stick position as a major awareness factor; there are too many variables that affect stick position for a given AoA. Nor is observed pitch attitude a great one for the same reason. Flap position drastically changes observed pitch attitude for a given AoA. In addition, observed pitch attitude gets very unreliable in mountains with seemingly-horizontal rock strata that's actually at a significant vertical angle; that's a common occurrence out here in the West. Since we don't have AoA indicators in GA planes, I think we're back to indicated airspeed, bank angle, and Gs being pulled. Not perfect by any means...

Posted by: Malcolm Ruthven | January 1, 2013 11:20 PM    Report this comment

Yes pitch attitude changes with flap position. But the stick position at stall will be the same for a simple flap. Not sure for something different like a sliding fowler flap as on C172. Mountains do complicate attitude control.

Learned stick position method after poorly and unsafely thermalling 'higher performance' gliders at steeper banks necessary, say up to 60 degrees necessary for soaring. Could not estimate bank angle well. Best thermalling speed is also an AOA.

Posted by: Ray St-Laurent | January 2, 2013 8:42 AM    Report this comment

Paul B stated: "The scenario Robert Johnson cited above is, in a way, putting the horse before the cart. The vast majority of these stall accidents are nothing so demanding as what's described. Before we get to that point, we need to get fewer people crumping in just ordinary base-to-final turns or hell, just in taking off. I'm not kidding. That's where a lot of the carnage is."

You're probably right. You're addressing the same issue I was trying to address, but you said it better. (BTW, I wish I did own a Bonanza :-) )

As Paul B. point out, these incidents are happening at takeoff and landing,in many cases to well-trained "stall-proof" pilots, as he noted in a previous post. I'm sure they had plenty of stall training at altitude. So, what is killing them down low? Are all these pilots really just incognizant of AoA, or is there something else we're not training for going on close to the ground?

I have the same question with ADS-B. I suspect if widely-deployed it will reduce cruise mid-airs, as the alarm will catch your attention when nothing else exciting is happening. But will it reduce the number of planes landing on top of each other on base-to-final? I think about that YouTube cockpit video of two pilots landing gear-up with the gear-warning horn blaring for 30 seconds prior, and wonder.

Posted by: Robert Johnson | January 2, 2013 11:48 AM    Report this comment

Isn't stick position kinda variable? Controls just aren't that consistent, especially between aircraft in a fleet. How do teach feel anyway? Sounds to me like a good bit of knowledge to transfer to a student, but not something you can standardize and depend on.

Posted by: Eric Warren | January 2, 2013 11:57 AM    Report this comment

One thing can kill you "down low" is a strong tailwind on base. The pilot is seeing high ground speed and gradually pulls back on the stick. A good solution for this is to announce that you are: " using right hand base for wind" and come into the wind on base instead. The moose hunter stall gets pilots because they have almost no low and slow and recent experience with slow turns.

Posted by: Bill Berson | January 2, 2013 12:02 PM    Report this comment

All of a plane’s controls are interrelated. Any idea that says we can move just one control and get 100% predictable results is likely wrong. This forum’s format does not allow a three hour debate, so everything is over simplified and thus “wrong.”

Stick position IS a good first approximation of stall IF you don’t change power, flaps etc. Of course the average flight will have a few different flap and power settings, so “Stick position’s” overall value is reduced.

Any way if you are interested in aerodynamics for pilots John S. Denker’s “See How It Flies” is the best info I have seen at any price, and it’s free. http://www.av8n.com/how/

Posted by: Robert Zylstra | January 2, 2013 12:13 PM    Report this comment

Lets see if the links works this time...

Any way if you are interested in aerodynamics for pilots John S. Denker’s “See How It Flies” is the best info I have seen at any price, and it’s free.

av8n.com/how/

av8n dot com

Posted by: Robert Zylstra | January 2, 2013 12:18 PM    Report this comment

Robert - ADS-B should make it easy for pilots to avoid mid-air collisions in the traffic pattern just as it should in cruise flight. It requires the pilot to pay attention to the information on his screen. While the situation on final with two planes very close together may be difficult to see on the screen (if there is no alarm) it is still easy for the pilot to see the situation building as he enters the pattern.

Gear up landings are a very different situation from mid-air collisions. It is a case of mental block - probably caused by outside influences rather than a training issue or a matter of situation awareness. An old friend told me the story of his "Attempt" to perform a gear up landing while completing a combat mission in an F-86 in Korea. He took a flare on final approach (a signal from an airman stationed on the ground with a flare gun for the sole purpose of warning a pilot his gear is not down), performed a go-around and did a normal landing. When he got back to base operations he was accosted by the tower controller who asked him why he didn't respond to the repeated warnings he was issued about putting his gear down. His answer: "I couldn't hear you because the gear horn was so loud."

Posted by: Paul Mulwitz | January 2, 2013 12:34 PM    Report this comment

Robert, for a run-of-the-mill, garden-variety stall accident, here's one from the 2010 data. You can all read it same as me:

www.snipurl.com/260x0v4

Nothing extra special about this. Looks like a stall/mush maybe into a spin on short final. Hard to tell exactly, but it was probably a turning stall provoked because the wings were loaded at slow speed.

I coded it as a stall. These baffling kinds of accidents are the ones we most need to address.

Posted by: Paul Bertorelli | January 2, 2013 12:41 PM    Report this comment

Bill Berson--" Perhaps some computer could correct for stick position changes. This way the pilot could at least get instant input with micro stick movements." If you were going to depend on a computer, would it not be even MORE advantageous to simply use "fly-by-wire" to limit control input, like Airbus? No thanks.

"Watching AOA instead of looking forward is hardly optimal as well." AOAs are color-coded and placed on the glareshield, within a pilot's peripheral vision. It hardly takes a lot of effort to discern fewer green LEDs--or a blue "On speed" light--especially compared to looking at and interpreting the airspeed indicator. That doesn't seem objectionable, does it? How would looking at the AOA be worse?

Posted by: jim hanson | January 2, 2013 1:00 PM    Report this comment

Thomas Connor--"don't almost all jets with pylon mounted engines slung under or over the wings also have a thrust line different from centerline?". EXCELLENT question.

They do, but it isn't the same in jetliners as light airplanes. A parallel observation--aircraft have "drag lines" as well--in a high wing aircraft, the drag is above the longitudinal CG. The difference in jetliners:

The "scale effect". In the Lake Amphib pusher, the thrust is about 6' above the longitudinal CG, on an aircraft that is only 23 1/2' long. Compare the approximately 8' offset of the thrust on a 209' length of a 777. The lever arm of the long fuselage tail ameliorates the offset thrust or drag.

It isn't just the Lake with the thrust line issue--the Twin Bee conversion on the Seabee has two high-wing mounted tractor engines. On my Kolb, every takeoff is full back stick to prevent the aircraft nosing over--so much for stick position.

Engines are often offset both vertically and horizontally to mitigate thrust line problems.

Posted by: jim hanson | January 2, 2013 1:36 PM    Report this comment

"It hardly takes a lot of effort to discern fewer green LEDs--or a blue "On speed" light--especially compared to looking at and interpreting the airspeed indicator. That doesn't seem objectionable, does it?"

This is an assumptive leap that springs from the position that AOA indicators are the lost holy grail. They may very well be. But we don't know that. We don't know that an AOA indicator placed on the panel or anywhere will help us or hurt us because no one has done the research in GA.

I have flown with three of the systems and I can tell you this: they require interpretation and thought. Some are better than than others, but they aren't just automatically intuitive because every one has a different display. There's no standard.

AOAI have worked well in two venues: military aircraft and some corporate jets, where pilots have formal training doctrine in their use. GA pilots don't, generally. With the wrong display, I can imagine making things worse, even though I like the idea of AOAIs in general.

Of course, glider pilots do okay with variometers, a quirky little instrument. But glider pilots are different and bring a different head to the game than Joe Bagadonuts in a Cherokee.

Posted by: Paul Bertorelli | January 2, 2013 2:13 PM    Report this comment

I agree that AOAs come in many presentations. Alpha Systems alone offers 9 different formats--from the old "lift reserve" gauge buried in the panel (not recommended) to the military/bizjet glareshield mount (Red/white/Green--hard to misinterpret those). At first, I thought that the LED glareshield mount was overkill and gimmicky--but after only 20 minutes, I had changed my mind. The colors are red/yellow/green, with one blue dot. Fewer lights mean less lift reserve. Changing colors indicates danger. Lighting up the single blue LED is "on-speed" and intuitive. It certainly isn't more difficult than taking your eyes inside the cockpit to look at an airspeed indicator--which gives you only an approximation of how close you are to a stall.

Maybe you are onto something with your glider variometer statement--audio varios vary pitch with different rates of climb or descent. Alpha Systems AOA has the same capability--even a no-extra-cost option of a spoken "STALL! STALL!. Hard to misinterpret that.

I only throw out the AOA and the realistic simulator ideas out there as something else to try. Let's face it--"practicing" at altitude hasn't been too effective in the last, oh, Century.

Posted by: jim hanson | January 2, 2013 2:44 PM    Report this comment

Actually, after I posted that, I realized there was a NASA study on this. Here it is:

www.snipurl.com/260ykcx

Some quotes:

"The results of these studies show that angle-of-attack infor- mation is a usable parameter, but not necessarily a superior one."

"Tests of the pilot's ability to take off and climb in a minimum distance from a standing start showed grossly inferior performance when the angle-of-attack system was used compared to that attained when airspeed was used."

"For approaches and landings, the angle-of-attack display was found to be of benefit when used properly in conjunction with other parameters, but it led to hazardous procedures and poor control techniques when used without the necessary understanding of how to use the display."

Interesting stuff. I'd call the results mixed. One finding is that flying approaches at optimum AOA resulted in lateral control difficulties for simply being too slow. That was my experience in experimenting with the LRI in our Mooney.

Posted by: Paul Bertorelli | January 2, 2013 2:53 PM    Report this comment

Throwing this out for comment--If we really want to cut back stall-spin accidents, what can we do short of limiting control (Ercoupe)? A thought--what about making the aircraft "stallproof" through leading edge devices? I have owned two Aerospatiale Rallye aircraft--they come with automatic leading edge slats. In side-by-side flyoffs (while at a glider contest) the 4-place Rallye beats the Husky in short-field TO & land--admittedly, with 35 more HP. Approach in the Rallye with the automatic slats just starting to creep out--there will be more than enough lift for the flare. I couldn't induce a stall--just a mush.

I've only flown a Helio twice, but the leading edge slats are independent--rather than joined like the Rallye. This supposedly prevents spins--though I never took it that far. Because it is a bush airplane flown "on the edge"--Helios certainly have their share of accidents--but are the stall-spin, or the normal bush-type collision with something on the runway?

Posted by: jim hanson | January 2, 2013 3:02 PM    Report this comment

I stopped reading these posts for a few days, and have only just come back to them now. Interesting discussion.

The physics of how and why airplanes fly is rather complex, but as others have pointed out above, the concept of angle of attack is relatively simple and easy to understand, at least on paper. But seeing it in action near the ground is another, and it can be very difficult to fight the natural instinct to want to raise the nose. Also as others have pointed out, most stall accidents are regular, boring 1G stalls.

I think what all of this can be summed up as, is a single word: discipline. That is, the discipline to do the aerodynamically correct thing, even when the sight picture out the window is primordially scary (i.e. seeing the ground rushing up at you).

(cont.)

Posted by: Gary Baluha | January 2, 2013 4:28 PM    Report this comment

(cont.)

One thing I have learned since getting my CFI (less than a year ago) is that explaining aviation to the uninitiated necessarily means simplifying things. The simplification will be technically "wrong", but you have to start with the basics. And as someone mentioned, private pilots don't need a doctorate in aerodynamics to know what they need to do. It's the discipline to do that, that is difficult.

On an introductory flight I was giving a few months ago, the aircraft I was flying was not producing the takeoff climb rate I was expecting. Yoke back pressure was increasing, airspeed was decaying, and we were headed into a stall. We were also climbing out of a valley (departing KDXR runway 17, for those familiar with the airport and area), and there are trees and a hill on either side, and more trees below. I knew the only way to get out of it was to lower the nose, which momentarily meant a zero (and even slightly negative) climb rate, but if I didn't, we'd certainly stall and all be likely killed in the crash. Even so, it was very difficult to fight the impulse to pull back on the yoke, and that, I believe, is what kills a lot of pilots. Not having the discipline to lower the nose, even if that means stuffing the plane into the trees.

(By the way, I managed to recover enough airspeed and energy to get a slow climb rate and circle around to land safely).

Posted by: Gary Baluha | January 2, 2013 4:35 PM    Report this comment

Jim Hanson- I was not suggesting any fly by wire ( never!). I was suggesting that a microchip could watch the stick position and compare throttle and signal the pilot instantly.The audio vario is another good example since it gives heads up information. But my point is that a stick position alarm would be instant. If you must wait 2 seconds for the wing to stall and then your AOA device sends a signal, it is already too late.

Posted by: Bill Berson | January 2, 2013 4:43 PM    Report this comment

Paul B., yes, I've seen that NTSB report before. It's what I personally categorize as a 'close-to-ground' accident (as opposed to 'far-from-ground', like a mid-air or LOC-in-MIC). More of the crazy stuff happens near the ground: crazy winds, crazy traffic, crazy distractions. In this case, crazy maneuvers. If that pilot had practiced that unstable approach at 5000' AGL, he would have spun the same way, but he'd still be here to talk about it. But how often do pilots actually practice at altitude like that? And do they then translate that experience to the different sight picture down low?

Maybe someday science will progress to the point where we can plug our brains into air-pressure sensors on the wing like a bird, or the engineers create stall-proof and darn-fool-pilot-proof planes. Until then, I think Jim Hanson's simulator idea is the nearest solution on the horizon. You can practice low-level scenarios safely, perhaps with a (mild?) electric shock on simulated ground contact to build the required muscle memory :-) The only other solution I see is to take the human out of the loop entirely, which is the direction the airlines, the military and even the auto industry seem to be heading. That's not the kind of flying I would enjoy, but it might work for those who see GA as just point A-to-B transportation.

Posted by: Robert Johnson | January 2, 2013 4:48 PM    Report this comment

Further to the safety of the Helio mentioned above--it has independent slats--if one wing starts to stall, the slat comes out automatically (actuated by air loads) to get it flying again.

I found an old pilot report in Aviation Consumer on the Helio (I have almost all of the back issues) with the following quote on the safety of the aircraft--"Our own scan of 30 Helio accidents reported by the FAA from January 1984 to May 1990 disclosed not a single fatality. The largest single cause of grief in Helios was main gear failure."

Considering that these aircraft are flown "On the edge" into areas that can often not even be called an airstrip--that's a good testimony to the safety record.

Posted by: jim hanson | January 2, 2013 4:51 PM    Report this comment

I flew Cherokees back in the early '70s and even took my private check ride in one. I don't remember any of the Cherokees I flew arriving at the flight line with a bagadonuts. Perhaps it is because they were USAF Cherokees rather than those inferior civilian ones? (They belonged to a USAF aero club.)

Posted by: Paul Mulwitz | January 2, 2013 4:55 PM    Report this comment

(cont.) Gary Baluha has the right idea. It's all about getting a human to intuitively grasp the concept of AoA, and then place it above the primal instinct to avoid harm or wounded pride. Even when the only option is the choice between the Oak tree or the Pine tree.

Posted by: Robert Johnson | January 2, 2013 5:07 PM    Report this comment

Bill Berson--"Jim Hanson- I was not suggesting any fly by wire ( never!). I was suggesting that a microchip could watch the stick position and compare throttle and signal the pilot instantly.The audio vario is another good example since it gives heads up information.

I'm not suggesting fly-by-wire control limiters, either--only that IF electronic warning of stick position were good, why not make it even faster and prevent the aircraft from stalling in the first place, rather than get into the entire "stick position" argument? If warning is good, wouldn't prevention be better?

"But my point is that a stick position alarm would be instant. If you must wait 2 seconds for the wing to stall and then your AOA device sends a signal, it is already too late." AOA's give you warning PRIOR to the stall--not AFTER. Nearly every jet airplane has a stick shaker and stick pusher to actively prevent the stall. If AOA-driven devices are good for jets, why not for GA airplanes?

Posted by: jim hanson | January 2, 2013 5:14 PM    Report this comment

Jim- I certainly don't need the complication and expenses of a stick shaker. I probably don't need anything in my Grob motor glider. The Grob shakes its tail at stall. I frequently thermal on the edge of stall, and just nudge the stick forward slightly to stop the buffet.

The Helio wing has large knife blade shaped spoilers to augment the short ailerons. This prevents aileron reversal and maintains good lateral control at stall. This is a nice feature.

Posted by: Bill Berson | January 2, 2013 5:37 PM    Report this comment

That's what I've been saying about gliders all along--but there seems to be a disconnect when it comes to power pilots--so a different solution is needed.

As for having electronics warn of "stick out of position", if you are going that far, why not make active electronics and actually DO something? It need not be fly by wire--almost every jet in the last 50 years (including the old Sabreliners I fly) has a simple AOA-driven stick shaker and pusher. You don't see many jets inadvertently stalling--if it works for jets, it will work for GA airplanes. We need something different--our "training" hasn't solved the problem since the biplane era.

Posted by: jim hanson | January 2, 2013 7:12 PM    Report this comment

---->>"Sometimes, a stall might result. I always found that the student almost instinctively knew what to do for recovery."<<---------

And there’s where training can change. While getting my ticket, I felt that while practicing slow flight that if the result was a stall, you “failed” the maneuver. The goal was to cautiously dance and maneuver around the stall, but never to see the stall, never reaching or knowing the limit.

Conversely, while doing stalls, the stall (and recovery) was the goal, the maneuver(s) leading up to the stall were moot.

Change the goal. While in slow flight, not only be able to recognize and prevent the stall while maneuvering, but also be able to stall (almost instantly) on command.

Posted by: Robert Ore | January 3, 2013 10:04 AM    Report this comment

Since Risk is Probability times Severity and we all; 100%, TO and LND, Paul’s list shows that LOC in Flight and LOC Ground equate to ~39% of VFR activity; and with IFR LOC; ~45%. Unfortunately, unknown is ~19% of the total and requires much more attention by the investigators. It is true that mid air equals 3% and icing is 1.5% but it always depends upon the daily mission profile whether it is a relevant concern. The Cirrus I fly out of Danbury is not immune to Stalls, LOC, or CFIT. I do not equate marketing claims to piloting skills. There have been many recent examples that demonstrate that hitting an 800 foot hill at night or LOC without stall recovery altitude will kill. I believe Paul’s thesis suggests: proper Piloting skills, no matter what the instrumentation in the aircraft; are essential when the ‘near earth’ safety margin narrows. There are many accident examples that indicate that Pilots; during a bad approach, take off, cross wind, or maybe lack of stabilized airspeed, Never Considered Permitting themselves a ‘Redo’, ‘Go Around’, or ‘Stop’. Watch the video of the Stinson 108 during a high, hot, heavy takeoff roll, roll, and roll. From my perspective, training gives us awareness of issues and permission to modestly adjust or re-fly as a corrective option.

Posted by: Philip Potts | January 3, 2013 11:10 AM    Report this comment

I'm going to approach this topic from a different perspective, namely my wallet and my heart. First imagine, that stall spin accidents went away. Hopefully our insurance rates would decrease.(wishful thinking I know).What an easy way to decrease our cost of flying. When you install an AOA system, the systems cost, is returned over the years by less expensive insurance from year to year. A gift that keeps on giving. Pilots are extremely cheap. If they saw the decrease in insurance expense I think they would go for the system. Then their is the cost of an actual Stall Spin accident. In terms of bad press for aviation, blaming the accident, once again, on pilot error, (stupid pilot tricks, darwin candidate etc.) families torn apart by emotional distress, loss of spouse all of a sudden an Angle of Attack system seems very inexpensive. Here is one inexpensive thing we can all do as pilots to improve aviation, and yet pilots are either too cheap, or in denial, (hey I don't need that thing.) From a statistical pt of view,and because the same accidents reacure year after year, seems like we do. I have a homebuilt aircraft with a AOA system installed and I love it. I flew in the Navy, off a ship for a few years, the Navy graciously provided me with hours upon hours of training in precise flying. I can't imagine flying without it.

Posted by: Carter Boswell | January 3, 2013 12:13 PM    Report this comment

The problem is many pilots will ignore the indicator when the ground is rushing up. About the only thing that will help this case is taking control away from the pilot, as Jim Hanson proposed several times here. I don't like giving up control. So I think a good partial solution is build airplanes (like the Helio) that has good lateral control. That way a pilot will land hard and break the gear, but survive.

Posted by: Bill Berson | January 3, 2013 12:41 PM    Report this comment

I suspect we all love the aircraft we fly. They meet the mission we most enjoy or perform. If we are lucky, we fly only one aircraft with a specific instrument configuration. The 2007 Cirrus I fly is an Avidyne system where airspeed is my AOA system. I don't care for the Helio even if it were new. Some of us fly various club aircraft which may have many instrument configurations or performance alterations. The Mooney Stall is more exciting than a Cessna Stall, but both can hurt us if we are inattentive during those 'Near Earth' flight profiles. I believe Carter is fortunate to have such a great training background with an AOA instrument. However in the heat of the moment, pushing the nose down toward the ground for airspeed may not be the most comfortable response a novice, under trained or low time pilot may perform. Air France 446 screwed up pitch control during a degraded instrument system failure. I'm all in favor with inflight information, but basic piloting skills do not 'Require' a PFD, MFD, or AOA. Whether we fly a Cub or a turbine, keeping track of the aircraft performance limitations are part of the scan methodology. True, specific instruments are part of our comfort zone yet speed, direction, and altitude remain the fundamentals.

Posted by: Philip Potts | January 3, 2013 1:38 PM    Report this comment

Massad Ayoob wrote 'stressfire', a book that teaches cops how to defend themselves in a gun fight and what to expect of their own behavior while being shot at. It's a mix of opinion based on eye witneses and the cop's recollection with occasional data from a camera and rounds fired. First is the surprise factor: No secrets here, but it takes a few shots to settle down and is why cops like auto-loaders: More rounds to 'warm up' with. What surprised me are two rules: Practice with the ammo you carry, and; Carry a gun as dirty as the one that shot the best group. The issue is dependability and predictability.

If we carry the analogy to airplanes, we break those rules by practicing maneuvers with a forward CG and light weight, then launch on an XC with an aft CG at MGTOW.possibly a high DA and gusty winds with no clue how it will handle. Google the Jessica Dubroff/Cheyenne WY Cardinal crash for an example.

Posted by: Thomas Connor | January 3, 2013 2:27 PM    Report this comment

pt-2 I have a theory that pilots of some aircraft don't get much experience with main wing stalls but instead learn tail stalls, so when a main wing actually stalls it's a surprise. I don't have what one would call data, and except for the NASA tail-plane icing research have zero support from others, so bear with me, this is just my silly idea.

In a plane like the C-182 with two up front, clean power off stalls are non-events, and power on stalls are not much of a problem either, even with sloppy rudder. But add flaps and we occasionally get elevator/stab pumping - what some attribute to main wing turbulence on the tail, but maybe its really the tail stalling. Add a little power and it goes away.

We put jugs of water in the cargo area to move the CG aft and it completely changes how some planes behave: They become delightfully light in pitch. Dangerously so, just like it will feel with friends and family on board. The elevator stab pumping disappears clean or dirty, and we get good stall breaks with a wing drop if careless with the rudder. All in all, less forgiving. No surprises there, but I don't think it is for reasons we are taught. If true, could this contribute to stall/spin accidents? While the theory might not be true, I doubt training with a forward CG reduces accidents.

Posted by: Thomas Connor | January 3, 2013 2:29 PM    Report this comment

Pt-3 I'm also not a big fan of more than 50% flaps in GA aircraft with a forward CG and low weight, especially Fowlers. I think they cause more grief than they solve and disabuse their use for landing in that configuration unless they are required. I prefer steep approaches with slips because they are instant on, instant off. The difference between landing distance and speed with and without 100% flaps is minimal, but the chance for trouble increases: With full Fowler flaps the center of lift moves aft on the wing so the nose rotates down, which 'consumes' stab/elevator authority, regardless if you trim off the pressure or decide to muscle it. Full flaps allow slower speed, which further reduces rudder and elevator/stabilator effectiveness. Unless there is a good reason for the lower speed I like to avoid full flaps and enjoy the benefits provided by more airflow over the tail: Better control effectiveness, less control pressures, more finesse.

Posted by: Thomas Connor | January 3, 2013 2:30 PM    Report this comment

Thomas,

I experienced precisely what you point out about fully loaded vs front seat only stall behavior in a DA40. With heavy load and aft CG that comes with it, the plane will actually try to stall in that horrifying way almost all planes do. :)

Using the ailerons stops working too. Luckily, I was with an instructor and we were doing it on purpose because I had totally been trained by repetition to expect a non event at stall. I have never stalled a older design fully loaded but I know to be ready to get right on it after the experience with the diamond.

Posted by: Eric Warren | January 3, 2013 6:00 PM    Report this comment

Does anyone have experience with the AOA indicator option in the Dynon D10A or D100? dynonavionics dot com/docs/D10A_intro.html It seems that for a few bucks more than the Alpha, Right angle or AFS AOAI units, one can velcro a Dynon unit somewhere and get AOA plus gyro backup in a small package. The Dynon AOA probe also provides ASI, and the Dynon can provide a density altitude readout, a real plus in my view.

Posted by: Thomas Connor | January 3, 2013 8:45 PM    Report this comment

A long time ago (1948) I learnt to fly. My Instructor was an Ex Royal Air Force Hawker Typhoon pilot who was over the beaches on D. Day. He stuck to the standard Air Force syllabus (which taught tens of thousands of pupils to fly) and I don't remeber too much Theory. With the grand total of 5 hours & 25 minutes he said, "Today we do Spins", and spins we did. He showed me one and then said "Have a go". I had a go with one turn and then he gave me another on with three turn of the spin & recovery. If you didn't want to spin you never went solo. I later became an Instructor in the early 1950s about the time people were starting to complain about being forced to Spin. Some bright spark (there's always one) mentioned the words 'Incipient spin', as if it would be a cure all. But most of us virtualy said "But who cares, we've done spinning so we will never be going anywhere near trying to pick an incipient spin." So I went on to a career lifetime of 21,500 hours in the air had never had a stall problem, even flying T Tail Jets. Forget the theory and get spinning. It's actually quite thrilling and you might even get to like it!

Posted by: Reginald Adkins | January 5, 2013 4:31 AM    Report this comment

I learned to fly 10 years after Reginald when spins weren't taught. I found how to do them in some book (can't remember which one) and simply taught myself. That book was correct and I happily spun Champs, a J-3, and Cessna 120s/140s for fun for quite a while, including spinning out of both slipping and skidding turns (which the book didn't teach). I stopped that as I switched to more advanced planes that weren't approved for spinning. Not sure if all that really helped me as a pilot, but it sure was fun.

Posted by: Malcolm Ruthven | January 5, 2013 5:23 AM    Report this comment

I just started re-reading Stick and Rudder, and the author goes over just about every argument posted here, for or against (or rather, "not for") AoA indicators, stick position as an AoA indicator, and so forth. Very early in the book.

Written in the 1940s, correct?

Posted by: Patrick Underwood | January 8, 2013 1:32 PM    Report this comment

Yep, I re-read it once a year. Over time, pilots tend to forget what kills them. Some rather intense ground school refresher classes might be good also, for older pilots, to supplement the flight review. This is just a suggestion, should not be mandatory. We don't need more rules

Posted by: Bill Berson | January 8, 2013 2:00 PM    Report this comment

Bill Berson--"About the only thing that will help this case is taking control away from the pilot, as Jim Hanson proposed several times here"

Where did I advocate taking control away from the pilot????

For those that think that "a pilot might not have the discipline to push the nose down while the ground is rushing up" after an AOA activation--why in the world would you think that they would magically have the ability to do so after a low airspeed indication (notoriously inaccurate) or any other stall indications? An AOA is just a tool, but unlike an airspeed indicator, it gives advance warning of a stall by displaying the TREND of reserve lift--letting the pilot know just how much is left. Why WOULDN'T a pilot want that--and what do you propose that is better?

Patrick--you are correct--the publishing date is 1944. Old Wolfgang probably had never seen an AOA at that time--or probably, even a simple stall warner.

Posted by: jim hanson | January 8, 2013 2:15 PM    Report this comment

Jim Hanson said: "I'm not suggesting fly-by-wire control limiters, either--only that IF electronic warning of stick position were good, why not make it even faster and prevent the aircraft from stalling in the first place, rather than get into the entire "stick position" argument? If warning is good, wouldn't prevention be better?"

Sorry, I really don't know what form of control limits you were advocating. But it seemed to me you were asking for some sort of automated stick control device.

Posted by: Bill Berson | January 8, 2013 3:18 PM    Report this comment

In 10 years, your airplane will be programmed with an instinct for self-preservation (inexpensively in non-certificated planes; very expensively for certificated). It will know to the microsecond its location and energy state, atmospheric conditions, and the location and velocity of all surrounding traffic, birds, and terrain. It will let you screw up as much as you like as long as you show no signs of killing yourself or committing a grievous FAA no-no within the next several seconds. But if you really start to go south, it will first object politely, then forcefully. Finally it will swear loudly while taking control away from you to save itself, and automatically log a Pilot-In-Command Control And/Or Judgment Error, with video and telemetry, to your real-time FAA flight record.

That is my bold and fearless prediction, and I'm only half joking.

Posted by: Patrick Underwood | January 10, 2013 9:47 AM    Report this comment

Add your comments

Log In

You must be logged in to comment

Forgot password?

Register

Enter your information below to begin your FREE registration