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LSA Crashworthiness

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Life is full of moral dilemmas and compromises and here's an interesting one: Does an airplane manufacturer—including an LSA manufacture--have a moral obligation to provide as crashworthy a design as technology and economics allow? The answer might be an easy yes, but then again, maybe not.

I got pulled up short on this by Aviation Consumer reader John Valldejuli recently. Based on our favorable reviews of the Pipistrel Virus, including gushing a little about its fuel economy, Valldejuli checked out the airplane for himself. Here's what he said: "Once I got into the pilot's seat, I wondered who would buy this plane? To me, it is downright dangerous, as the main wing spar intrudes into the cockpit crossing just a little bit in front and above your head ( I am only 5 feet 9 inches tall). In a not-too-perfect forced landing, your head could easily be crushed by the impact with the main spar." Between the lines, he was inquiring why I hadn't noticed this in my review.

The fact is, I did notice it, I just didn't mention it. Why? It has to do with my peculiar background and experiences—flying and jumping out of airplanes, riding motorcycles and so on. Further, I tend to elevate things like speed and economy above safety and comfort, nearly to a fault. Because I think I understand the risks associated with these tradeoffs, I have a low expectation for crashworthiness in airplanes in general, but more so for LSAs. I think it's all but inarguable that given the minimal structure in a 1320-pound airplane, it's not reasonable expect it to be as crashworthy as a heavier Part 23 airplane. For me, crashworthiness in LSAs is not the same as for Part 23 aircraft. If you want an airplane as crashworthy as a Part 23 airplane, buy a Part 23 airplane.

That's probably an overbroad generalization because I suspect that some LSAs are more crashworthy than others. I just don't have any meaningful data to rank these airplanes. But I think Valldejuli is correct. The Virus is compromised toward performance and safety, but that spar intrusion diminishes its crashworthiness in a way that other designs don't. A basic principle of crashworthiness is generous flail space inside the cabin, so in a crash, your extremities don't collide with something hard. Because of their cabin size, LSAs just don't have the flail space of, say, a Diamond DA40 or a Cirrus SR22. In my view, the Pipistrel Virus may have even less because some of its speed comes from low drag and low frontal area. That translates to a small cabin whose crush and flail space is minimal.

This is the very reason that Diamond declined to enter the LSA market. Diamond CEO Christian Dries is adamant that a manufacturer owes its customers the best crashworthiness possible and his airplanes have the unassailable record to prove that he's not just talking the talk. Further, he thinks that with regard to safety in general, the regulators' 1320-pound limit is artificial and sheer lunacy. I can't argue the point. In a sense, Dries is on the same page as I am. LSAs and real crashworthiness may be mutually exclusive.

By the way, Pipistrel doesn't see it this way. The company's Tine Tomazic told me he believes the Virus, with its beefed up A-pillars and spar cage and strong carbon fiber construction is actually more crashworthy than other designs. Pipistrel sees the spar intrusion as a net positive, protecting the occupants against a tree or other object slicing into the cabin. (I'd still pick the Virus as the LSA of year, by the way.)

For me, the eureka realization in all of this is that I have to recuse my high-risk tolerance sensibilities and make a note to report such things as Valldejuli's observation about the Virus spar intrusion. Doing so doesn't condemn the airplane nor suggest that a buyer shouldn't buy it. What it does do is illuminate a potential compromise that the reader can then evaluate guided by his or her own sensibilities.

That's about as direct a means as I can devise to say that it's not just manufacturers who have moral responsibilities. So do journalists.

Editorial addition 9/14/2012. What follows are the two texts mentioned above in their entirety. I did not include them originally because I try to get out of blogs in under 600 words. With these texts, it's closer to 1700. These are routine editing decisions and not an attempt to smear anyone or suppress information.

The context is this: I picked the Pipistrel Virus as the LSA of the Year. I picked the company as the Innovative Company of the Year. Nothing in the foregoing would make me reconsider that, but that's not the same as companies and products being above criticism. Reader Valldejuli questioned my judgement, fairly I think, because his letter reminded me when I got into the Virus, I scuffed my head on the spar and when I got out, I did the same thing. Why didn't I mention it in my report? Because it seemed minor to me and not worthy of comment. While I don't share his view that it's an unacceptable safety hazard, it is still my duty to make note of it. And that's the point of this blog.

Dear Aviation Consumer:

I really enjoy your publication and find it well worth the money. However, I must disagree with you on a Gear of the Year choice.

Flying a Piper Archer II, mostly by myself, I drooled over the gas mileage of your BEST LSA: PIPISTREL VIRUS. So I flew to the SLA showcase in early 2012 at Sebring, Fl airport to get a closer look at the Virus. Once I got into the pilot’s seat, I wondered who would buy this plane? To me it is downright dangerous as the main wing spar intrudes into the cockpit crossing just a little bit in front and above your head ( I am only 5’9”). In a not-too-perfect forced landing, your head could easily be crushed by the impact with the main spar.

I mentioned my extreme concern to the salesman who responded that, “You lean forward in front of the spar just before impact”... then I surmised the back of my head could be crushed as the indeterminate g forces toss my body - and head - around in milliseconds, seatbelts notwithstanding. I thought it a silly assumption that I could control where my head was in a uncontrolled crash with water or a fixed object like a tree. I surmised that not even a motorcycle helmet would save my life as my neck would be broken.

In my opinion, this airplane would never comply with the safety portion of Part 23 certification, and it certainly does not meet the “common sense” certification. ( I can just hear fellow pilots at my funeral, “Too bad his head got crushed, but he sure did get great gas mileage while he flew!”)

We as consumers must consider all of the possibilities – planes do crash land, both on land and in the water; and when they do, you may not be in control when you strike a stationary object or water as the g forces will be just too great. It is sort of the like the fool who does not wear his seat belt in a car because he thinks he can control how his body will react in accident. Anyone who has been in a bad accident knows the folly of that thinking – it is quick and with great force.

New LSA airplanes are great and Viva la Innovation, but I have to thank Piper, the FAA, and Part 23 certification for really considering – and testing - the crashworthiness of my Archer II.

John A. Valldejuli

Response from Pipistrel's Tine Tomazic

While I am quite a bit taken aback by the tone of Mr Valldejuli, I am happy to comment on this.

The cockpit design is made of Kevlar reinforced composites and the seat belts designed so that the head passes well below the main strut. I am 5 ft 9'' myself and have never head an issue bumping into any structure. We have had serious crashes because of pilot error, and even there – none of the occupants bumped into the spar which Mr Valldejuli claims to be »in front of his head«. What everybody forgets is that your head is »hinged« to the body at the bottom of the neck – and not on the forehead. Hence in an impact, the head goes DOWN and not forward (you can see this in car crashes as well – this is why airbags are coming from the steering wheel, which is well BELOW the eye (forehead) level, and not from the windshield somewhere).

Also, I am sure that there was a misunderstanding on what exactly the salesparson told this gentleman. It is common sense that you do not lean forward when the situation becomes an oh-shit moment! I do not know how the cockpit demonstration went for Mr Valldejuli, as I was not present, so I cannot directly comment on that. What is for fact is that »leaning forward before impact« is not our design principle behind cockpit safetyJ

Further, because the spar is in the location of where it is, it makes the cockpit MORE safe, because an impact into e.g. a tree branch will be stopped by the spar and not fly freely through the cockpit into someone. You have flown the Virus, you saw where the spar is relative to oneself. When comparing the Archer II to the Virus – ever wandered what happens when the aeroplane rolls over on ground. It is one of the most typical crashes, e.g. nosewheel brakes off then the nose dips into the ground. Archer has no roll cage (like Virus, Panthera, even Taurus in our case), but the occupants heads would simply be squashed. Is that what makes an aeroplane so great?

I am not saying our design is perfect, but there definitely was a lot of thought in its execution and keeping everybody safe. We have not had any deaths related to accident head trauma, and people were involved in ditching, even crashed into a mountainside in a white-out situation. In our view, we view our cockpit design safe, in fact, much safer than most aeroplanes. When strapped in, you are sorrounded by Kevlar reinforced element and energy absorbing zones from all sides, with the main spar protecting you from above (roll over), the A-pillars/spar cage (forward impact), undercarriage uni-element design (below) and collapsable fuselage ribs (behind).

To put things into perspective: On thanking FAA and Piper for the crash tests – Crash test for small general aviation was imposed by the FAA with the »The Dynamic Crashworthiness Requirements« detailed in FAR23.562, first issued in August 1988 as part of the FAR-23 document. This was then further explored during the NASA/FAA AGATE program in mid-1990. My point here is that the Archer I (certified 8 July, 1975), which Mr Valledejuli references, was NOT even tested for Crashwortniess, despite his claims.

Thank you and best regards,

Tine.

Comments (98)

As you note, Paul, life is indeed full of compromises. In fact, you could almost characterize life as just one continuous series of compromises, some big, some tiny.

Those of us with a libertarian bent tend to accept this, while control freaks think they can eliminate them via regulation and restriction and lawyers make mucho bucks by convincing brain-dead juries that they are never necessary.

With LSAs I would say go with noting the bad along with the good, maybe consistently working in a reminder that LSAs and even more so their lesser brethren the ultra-lights inherently represent various degrees of compromise in crashworthiness.

Posted by: John Wilson | September 12, 2012 7:32 PM    Report this comment

I can't agree with much of the article, based on my experience with the market-leading LSA, the CT line from Flight Design. The CT was designed with a protective "pod" around the occupants. The materials are extraordinarily strong, due to the carbon fiber and Kevlar construction. At the same time, the materials flex to absorb energy. Many pilots and passengers have walked away from crashes that would have crumpled most "spam cans". The my knowledge there hasn't been a fire associated with any US accident. The CT has lots of "flail space", more than most older Part 23 aircraft. Yes, there are some flimsy LSA aircraft, but don't include the CT among them.

Posted by: tim greer | September 13, 2012 1:15 AM    Report this comment

What I find striking about this article is how unconsidered and skip-shod this whole 'analysis' is. There is no excuse for having 'no meaningful data' LSA is new, but there is data out there if the author had cared to spend any time looking. The excellent Nall reports, on AOPA, would be a good starting point. While they don't break out LSA planes by category, they do break out by pilot types. Taken over the last two available report years, 2009, 2010, Sport pilots (who only fly LSAa) have a lethality rate (per hrs flown) HALF of that for comparable SEL planes (also defined as deaths per flight hrs). To be fair, the DA40 scores excellent in these reports (Mooneys are killers). Randomly equating crashworthiness to flail room is just pointless guesswork. Really slow stall speed and resistance to stall likely has more to do with the better LSA safety record. In 6 years noone has yet killed themselves in a CT with over 360 deliverd just to the US. Then again, the cabin is actually wider than that of a C182. Lot's of supposedly useful flail room.

Posted by: Kurt Kuhlmann | September 13, 2012 3:07 AM    Report this comment

Paul B, let me first praise your list of features to trade off in aircraft design: Speed; economy; safety; and comfort. Each of us might choose different features to maximize, but the list is equally valuable to all.

I suspect there are some easy choices to help crash worthiness. One example is the tractor engine position. If the engine is the first thing to hit a fixed obstacle it will absorb energy. If a pusher arrangement collides with the same object the engine just might end up on your head.

I'm not sure I agree with your assessment that 1320 pounds means poor crash worthiness. The light weight also means slow stall speed and the possibility that a collision will happen at a slower speed than a similar event with a part 23 plane. I've been convinced for a long time that lighter is better when it comes to aircraft. Crash worthiness might be sacrificed with this notion, but I'm not sure that is the case.

(I am sure light wing loading means lousy response to turbulence.)

Posted by: Paul Mulwitz | September 13, 2012 5:03 AM    Report this comment

"there is data out there if the author had cared to spend any time looking."

Contrary to your asserttion, the author has looked. What the accident reports do no provide is impact energy assessments and the nature of any injuries sustained by occupants. These are the touchstones of crashworthiness. Accident rate and crashworthiness are two different things.

You claim lethality rate of half certified airplanes? Cite me the data that compares hours flow to accidents encountered--in other words true exposure. If this exists, I haven't found it.

If you don't have the hours exposure, you don't have meaningful rates, therefore your comparison is flawed.

Posted by: Paul Bertorelli | September 13, 2012 5:17 AM    Report this comment

If you fly a Virus, why not wear a bicycle helmet? For that matter, a helmet might be a good idea in any airplane.

Posted by: Larry Rice | September 13, 2012 5:57 AM    Report this comment

Paul: Its difficult sometimes for people who are experts in a field to recognize what most people don't know, almost as difficult as for people who are not experts to recognize what they don't know. Checklists can help. Perhaps the work could be enhanced if there were an expectation that each flight review would address: design for safety (with designated subtopics like spin resistence or recoverability, annunciation of things like angle of attack or stall warning, fuel state and so on), design for crashworthiness, speed, comfort, economy, ease and frequency of maintenance, ease of entry and exit, cockpit lay-out, cockpit visibility, available instrumentation and options, baggage capacity and loading effort, cost. I'd also add insurability reported in ranges by pilot hours; that kind of information may be hard to come by for a new design, but since insurers have to answer the question when owners come looking for policies, it seems to me the insurers can answer it within ranges or with appropriate caveats when a reporter calls. It would really enhance the value of flight reviews (of both new designs and established ones, even legacy aircraft still being traded in the market) if every flight review reported a reasonably thorough and comprehensive list of points like this.

Posted by: Joe Corrao | September 13, 2012 6:35 AM    Report this comment

If you are going to make a pronouncement about LSA safety, why not at least back it up with some statistics instead of observations about "flail room" and the location of wing spars? You totally neglected the role of stall/landing speed reducing the energy in a crash landing, the shielding/crumpling energy absorption of a high strength carbon fiber cabin, and the ultimate backup of a BRS. The ability of Flight Design aircraft to protect it's occupants in a crash is well-known and appreciated by it's owners.

If you really want to dig into the meat of small aircraft safety, why not discuss the relative safety of high-wing verses low-wing design?

Posted by: Jim Stewart | September 13, 2012 6:41 AM    Report this comment

I equate 'flail room' with dissipation of energy. If the plane is flying slower ~32 kts, there is less energy to dissipate. I wonder if BRS should be included in this discussion.

Posted by: Dave Fisher | September 13, 2012 7:27 AM    Report this comment

I'll take a 30ish knot stall speed and a ballistic parachute with a kevlar cabin (carbon fibre breaks sharp remember! Thus kevlar which is energy absorbent and no sharp edges when it breaks) over more cabin flail space in my opinion.

Posted by: Dave Bowman | September 13, 2012 7:31 AM    Report this comment

I just looked and saw on their website that the Pipistrel airplane cockpits are made of Kevlar not carbon fibre as the rest of the plane is

Posted by: Dave Bowman | September 13, 2012 7:41 AM    Report this comment

As you said it is all tradeoffs. Which factors are more important. At least in LSAs we get some choice in our purchases. In Part 23 and more so in Part 25, the FAA decides for us what is most important. We might be safer, but it is certainly more expensive and therefore we are all flying less.

It is the same in cars, different mandates (Air bags, emissions, fuel economy)drive up the cost. This means more people are driving older LESS SAFE cars. It is a counterproductive strategy. But so are most government strategies.

Posted by: Roy Zesch | September 13, 2012 7:56 AM    Report this comment

The ability of Flight Design aircraft to protect it's occupants in a crash is well-known and appreciated by it's owners.

Noted. Cite the data, please. What's the source of this claim?

In attempting to put relative safety in perspective, you have to understand that detailed data on the nature of injuries sustained in GA crashes is simply not available in sufficient quantity to make conclusions. The reports simply say "injury" or "no injury." Sometimes not even that.

It other vehicle studies of all kinds--mostly detailed research on cars--there is positive correlation between vehicle weight and lower incidence of injury. This has been long established and one reason for it is the inclusion of additional structure.

A Part 23 airplane typically weighs 300 to 500 pounds more than an LSA and 600 or 700 pounds more than an LSA that's really an ultralight.

So, is what's true in automobile crashworthiness just the reverse in airplanes? Christian Dries--who is in both the car and the airplane business--argues that the principles are the same.

If they are different, tell me why. What is the logic of this argument? What proves it to be true?

Posted by: Paul Bertorelli | September 13, 2012 8:10 AM    Report this comment

The public purpose of allowing "amateur" built aircraft is partly to advance the knowledge of aviation technology. Experimentals have been exploring the ramifications of building small and light for a long time now, in a way and to an extent for which there is no economic incentive for commercial builders. There really SHOULD be a lot of information about the effects of all these competing design features by now, despite LSA's as a class being relatively new.

The fact that there is not is partly because we have allowed insurers and regulators to drive the data collection (and their purposes are quite different) rather than designers and builders/users. We should, by this time, have a good understanding of the behavior of these specific design features in actual crashes. But the reports are focused on broad trends and aggregate numbers, not on providing detailed grounds to actually guide a designer in making these necessary compromises.

As an engineer I can tell you this information exists in most other industries, and I suspect it also exists in the large, expensive end of aviation design. Homebuilders and experimental designers should have been compiling this knowledge in a disciplined way all along, and the alphabets whose purpose includes advocating for experimentals should have been facilitating the effort.

Posted by: Glenn Killinger | September 13, 2012 8:31 AM    Report this comment

There was once a saying invented by the auto industry “Its the nut behind the wheel that kills” In avaiation “It's the pilot that crashes”. Sound familiar? The auto industry was forced to rethink its attitude and a lot of R&D went into providing a safe environment inside, outside and around the motorcar. What has happened to the aircraft we fly? Uuuuuh nothing maybe! We still have a high speed heavy object being flung round and round out front of the aircraft, with the most inefficient means of propulsion known, two long planks called wings each side of the aircraft and other items sticking out of the vehicle. How much has the GA aircraft design changed? This question includes the LSA's.

The car is a lethal weapon both past and present. New technology has being developed to stop the car before it hits someone and is presently being put into automobiles. GA aircraft on the other hand is not so lethal (try flying into someone on the ground and actually hitting them) but public perception dictates differently.

Yes we need to look at crashworthiness in all GA aircraft and get the authorities to change that which they have failed to change before.

Posted by: Bruce Savage | September 13, 2012 8:50 AM    Report this comment

Many high wing LSA have a carry through spar near the pilot's head, so one assumes many builders have thought of it's safety aspect. Saying that means the pilot's head would contact it on a crash is speculating. The Flight Design CT models have OEM four point harnesses that restrain the pilot. We could add third party airbags if we thought it important. Restraining the body may be the safer alternative to letting it "flail" around. I feel well restrained in my CTSW.

Posted by: Jim Meade | September 13, 2012 9:35 AM    Report this comment

Paul B. I can think of one argument for the notion that heavy cars are safer but lighter airplanes might be the best choice. In the case of car accidents the most likely object to hit is another car. It seems obvious that a heavy car colliding with a light car will fare better in the collision. In the airplane accident case, collisions are much more likely with fixed objects like trees, buildings, or granite clouds. In that case it seems the reduced impact energy of a lighter plane might make the collision less damaging than a heavier one (M V squared?)

I personally don't subscribe to this argument. I just wanted to make it to answer your request for one. The lighter plane will certainly travel faster on less fuel for the same distance than a heavier one. That is why LSA can generally get upwards of 25 mpg while part 23 planes are more likely to be under 15 mpg -- some a lot under 15.

Posted by: Paul Mulwitz | September 13, 2012 10:02 AM    Report this comment

I am generally dissatisfied with so called journalistic standards. Wouldn't the normal standard be to find a source to comment on the flail space issue and include balance by allowing Pipistrel to comment?

Given the lack of real data I have no problem accepting the author's judgement followed by balance. I think it is morally problematic not to use ones own judgement rather than exclude something for lack of a source. The author's beliefs intrude everywhere, and hiding behind sources and balance is often done to justify an author's agenda.

I applaud your even considering the ethics here, and say that if you think there is an issue, you should include comment. Simply do as you have done here, qualify your statements as unscientific and allow the balancing comment. We disagree all the time, but I respect your expertise all the same.

Posted by: Eric Warren | September 13, 2012 10:18 AM    Report this comment

Eric, did you miss the segment quoting a response from Pipistrel? It's up there.

And a note on blogs, which is what this is. Blogs in our context are considered to be informed opinion, not news columns. This is not an "article" or a "news story." It is informed opinion. (If you'd claim it's ill-informed, have at it. I have a thick skin.)

Posted by: Paul Bertorelli | September 13, 2012 10:38 AM    Report this comment

Paul, I see nothing in your AVWeb article that represents a serious technical assessment of LSA crashworthiness nor of risk factors for occupant injury.

Evaluation on the basis of our "own sensibilities" may be all we have, but it is a poor substitute for actual evidence. As you say, above, "Cite the data, please".

Posted by: Fred Gerr | September 13, 2012 10:41 AM    Report this comment

Kurt, what are the claimed fleet hours for the entire Flight Design fleet in the U.S.? I'd want to calculate some rates.

Posted by: Paul Bertorelli | September 13, 2012 10:42 AM    Report this comment

This discussion reminds me of Nader's book "Unsafe at Any Speed: The Designed-In Dangers of the American Automobile" where he accused U.S. auto makers of knowingly producing cars that endangered public safety all for the sake of profit. His conclusions were wrong, but the auto industry suffered just the same.

Posted by: Dave Fisher | September 13, 2012 10:56 AM    Report this comment

Paul B, I don't have any precise data on Flight Design, but I do have anecdotal information gained by hanging around mechanics at my local airport. It turns out to be very rare for a private airplane owner to fly over 50 hours per year and many fly less than 25. I think if you multiply the number of Flight Design planes by 50 you will get a reasonable estimate of the hours flown. The key is to understand that LSA, like experimental aircraft, cannot be flown for commerce. That means each plane will probably get a lot less exercise than the typical rental aircraft.

Posted by: Paul Mulwitz | September 13, 2012 11:03 AM    Report this comment

This was not one of the best articles I have read lately. There was no real analysis, journalistic standards seem to be pretty loose and shoddy. I fly a CTLS and unfortunately it has been through several incidents including a hanger falling on it and tazing into an unmarked/not-notamed ditch. The CT was intact booth times--I feel safe in the plane. My wife and I use it for pleasure trips and love it. I fly at lease weekly and 500+ hours since new (2008). Dumb article!!!

Posted by: Kenneth Nolde | September 13, 2012 11:28 AM    Report this comment

Paul... I appreciate where your article is coming from... we all (esp. journalists) tend to gush over specs and features, while politely ignoring things like company viability, parts, service, or safety. But you said it yourself... this is an "overbroad generalization". Flight Design's "safety cell" was designed with things like load transfer, crush zones, and energy dissipation in mind. Anecdotal evidence shows 6+ years worth of crashes where the impact was significant to the point of nothing being left but the cabin, and the occupants walked away. Last week in Michigan is a good example. BTW, I believe the wing spar was implicated in a head bump/cut... but they walked away. As a CT owner, I've morbidly poured over reports and pictures from 6 years worth of crashes... the Safety Cell works. If you were to create a rating for "Crashworthiness", how would a 'Chute figure in?

Posted by: tim greer | September 13, 2012 11:37 AM    Report this comment

As an old but not nearly so bold pilot as I once was, and being one of those "nuts" who installed seat belts in cars that came from the factory without them, I've certainly noticed how little occupant protection our airplanes have--whether certificated back in the dark ages like most were, or more recently, such as the LSAs. The fact is that in an emergency landing off field, unless the landing is close to perfect, someone is going to get hurt, more or less.

What can we do as owners to minimize this predictability? We can install shoulder harnesses (3 point, 4 point, or even 5 point), or air bag harnesses (I have BAS 4 points in my 1963 P172D). We can insist that our passengers stay buckled up. We can replace sharp switches with rockers, or we can pad them in some reasonable fashion. But we can't account for stupidity.

Years ago, I did some volunteer observation flying with the local Sheriff. He was trying to decide whether the cost of being able to patrol the county at night to discourage property crimes could be minimized if an airplane was used instead of a fleet of patrol cars. So one night, as we were getting ready for the flight, I buckled up the 3 point belt in the 172, and he just buckled the lap belt. He said, "I'm not going to put this damn shoulder belt on--it's too uncomfortable." My response: "I don't care whether you do or not. If we crash on take-off, it's your teeth that will be embedded in the dashboard." He buckled it.

Cary

Posted by: Cary Alburn | September 13, 2012 11:57 AM    Report this comment

Paul,

You seem to be determined to disagree with me. Why? Please read my post again.

I think you were fine not bringing the spar up originally, and give you a plus for your thoughts here. My point is that your blog standard is, IMO, better than the standard which is easily abused.

Posted by: Eric Warren | September 13, 2012 12:15 PM    Report this comment

Cary,

Maybe Pipistrel should put an airbag on that spar? Assuming it wouldn't be too close or something.

Posted by: Eric Warren | September 13, 2012 12:18 PM    Report this comment

By Paul’s logic, a ‘56 Chevy is safer than a 2012 Chevy because it is larger and beefier with more flail room. I think not. But this shouldn’t be about guessing. In some cases we have a lot of experiential data, as noted in this string, but in all cases we have incredibly sophisticated engineering analysis that can predict with great accuracy the crashworthiness of any structure.

Further, the factors of gross weight and stall speed are huge in this regard! Crashes are all about energy dissipation. With a lot less energy in an LSA than in my Bonanza, and with the application of computerized engineering structural analysis, I think I would feel safe in an LSA. Of more concern to me would be the much reduced flight envelope - they are much more prone to getting blown around uncontrollably, like a leaf. I think.

Moral of the story - we don't have to guess. Let’s get a proper evaluation of this topic! The LSA category is now mature enough to have decent data available. And if LSA certification doesn’t require modern structural analysis up to some standard, then it should.

Posted by: James Herd | September 13, 2012 12:25 PM    Report this comment

"It turns out to be very rare for a private airplane owner to fly over 50 hours per year and many fly less than 25. I think if you multiply the number of Flight Design planes by 50 you will get a reasonable estimate of the hours flown."

That won't work, Paul. Many of these LSAs are used in flight training, so they accumulate 400 to 500 hours a year. I usually rely on manufacturers to provide their own estimates, then smell test it with a formula I've developed that has proved reasonably accurate.

Using 50 hours a year, you'd very generously come up with 110,000 or so fleet hours. And that assumes Flight Design has had 300 airframes in the U.S. since 2005. It hasn't. The volume has ramped up slowly. If I can get accurate data, I can calculate rates. It could very well be the fleet hours are higher. The fatal rate is easy. It's zero.

"The LSA category is now mature enough to have decent data available."

This is the problem, James. It isn't. I have been accumulating data for several years on it and the numbers are too small to make reasonable conclusions. Something like 150 accidents during the study period across dozens of models.

When I did this for certified airplanes--many more airframes and many more hours--the data has to be qualified as limited by small totals. For LSAs, it's worse. (Cirrus alone has 170-plus accidents in 5M flight hours. Still very small numbers by accident statistical standards.

And that's why I say meaningful data isn't available.

Posted by: Paul Bertorelli | September 13, 2012 12:45 PM    Report this comment

Not disagreeing, Eric. Just pointing out I did get a response from Pipistrel.

Posted by: Paul Bertorelli | September 13, 2012 12:50 PM    Report this comment

Sure, no “scalpel” or “surgical” statistical analysis can be made from limited LSA data, but I still think we can start to draw useful statistical conclusions from 150 accidents, even though I realize it is a broad category of aircraft.

But my point is more profound than that. Why does it take a very competent and insightful journalist, along with a bunch of us hecklers, to shed some light on this topic? Shouldn’t the FAA, NTSB, AOPA, and EAA be working on this type of project on our behalf? Don’t they have the necessary professionals and financial resources to get past all of our amateur bloviating? Isn’t this a good illustration of what is wrong with small G.A.?

We have all been skillfully (even if not intentionally) wrapped around the axle with “silly topics” that are little more than unnecessary distractions. And it is the same organizations I mentioned above that seem to be in collusion! Examples - promoting 406ELTs that fail most of the time, and ADS-B that brings little value to many of our cockpits. (Thread hijack!)

Posted by: James Herd | September 13, 2012 1:09 PM    Report this comment

Ahem. Back to the original point, safety issues in Light Sport Aircraft. I can't deal with journalists and morals. Despite the low weight of S-LSAs, it is possible to improve their safety. A wing spar that stands ready to bop the pilot's head is a no-brainer: it is a bad idea. How about safety harness? The beautiful, lust-worthy Tecnam P2008 I got to fly at Mt. Vernon had only an automotive-style across-the-chest shoulder harness. I think that is unacceptable and dumb. How about securing the shoulder harness so as to prvent spinal compression in a crash? How about reducing the number of sharp things in front of the occupants? Choosing Kevlar rather than carbon fiber for the crash cage? And so on. I know most LSA makers are small companies w/o big engineering staffs, but I suspect there are numerous engineers who'd be delighted to consult on such matters for affordable rates. Incidentally, I point out that we don't think of J-3s, T-crafts, and Champs/Chiefs as "ultralights," yet they are in the same weight category as S-LSAs. Low mass and slow speed are entirely consistent with safe, delightful flight... and attention to safety.

Posted by: Hunter Heath | September 13, 2012 1:19 PM    Report this comment

"Shouldn’t the FAA, NTSB, AOPA, and EAA be working on this type of project on our behalf?"

I think this will eventually get done. The NTSB just finished with an examination of amateur-built airplanes. I'm sure LSA will come up, too. Like the rest of us, they have limited resources. I've been accumulating data over the past few months, but it's slow going and conclusions are iffy.

Posted by: Paul Bertorelli | September 13, 2012 1:40 PM    Report this comment

"Shouldn’t the FAA, NTSB, AOPA, and EAA be working on this type of project on our behalf?"

I think this will eventually get done. The NTSB just finished with an examination of amateur-built airplanes. I'm sure LSA will come up, too. Like the rest of us, they have limited resources. I've been accumulating data over the past few months, but it's slow going and conclusions are iffy.

Posted by: Paul Bertorelli | September 13, 2012 1:41 PM    Report this comment

Referring to the airplane/car analogy, I understand that while passengers in heavier cars suffer less in a crash, lighter cars are often safer because they are more manuverable and able to avoid many crashes entirely. In addition, SEL aircraft are routinely flown in more challenging weather conditions than most LSA's making safety comparisons between the two a complex undertaking.

Posted by: Jennifer Carr | September 13, 2012 2:22 PM    Report this comment

The bottom line in all airplanes, is that they are designed for "airworthiness" first. Crashworthiness is a consideration far down the list in the initial design, if it's really considered at all.

I've yet to fly a Part 23 aircraft that felt like any thought was given to crashworthiness in it's design. A C-172 would only have two seats if they devoted extra weight to making it more crashworthy. Would that make it any more likely for the pilot to survive a stall / spin in the pattern?

I previously owned a Flight Design CTSW. I have been impressed with how well the cabin has held up in crashes, and the BRS was an additional safety factor as well. However, the BRS is there only to soften the impact, and give you a chance to survive something that you might not otherwise.

Face it, most airplanes that Private Pilots or Sport Pilots fly, would not get off the ground if they were truly crashworthy. Or they would be so inefficient that cost would suffer greatly. No one would buy an LSA that required a 180 HP engine, burning 10 GPH, to cruise at 100-110 Knots, with only one person on board.

When has the FAA ever given thought to crashworthiness of a non-commercial GA aircraft? Yes, they look at stall speeds, oxygen requirements, spin recovery, etc. But those are airworthiness issues, not ground collision worthiness issues. Some of them help to keep you from colliding with the ground more often, but have nothing to do with survivability if you do so.

Posted by: Roger Fane | September 13, 2012 2:37 PM    Report this comment

Jennifer, if you like digging through data, check this out. Lots of interesting stuff:

www-nrd.nhtsa.dot.gov/Pubs/811659.pdf

Posted by: Paul Bertorelli | September 13, 2012 2:48 PM    Report this comment

Good points all, Roger. Lest we forget, typical GA accident rates are around 7 per 100,000 hours flight time with fatal accidents in the region of 2 per 100,000 hours. If all were fair and equal this suggests a private pilot with a lifetime experience level of 500 hours has less than 1/2 of 1 percent likelihood of experiencing an accident. In reality we all know most accidents result from pilot error so a "Good" (safe) pilot would face less risk than that while a not so good pilot would face more.

In that context it makes sense to focus more on airworthiness than crash protection.

Posted by: Paul Mulwitz | September 13, 2012 4:21 PM    Report this comment

Paul,

Lol, once again, you are disagreeing with me in error. I stated that you properly allowed the balancing statement. I know I am not a good writer, but was I really that discernible?

Posted by: Eric Warren | September 13, 2012 6:39 PM    Report this comment

Paul, Okay, now I've done it to you. You weren't disagreeing,, as you say, but it seemed like you were. Oh well,

Ahem, Ahem.

Back to the actual subject, not safety, and not journalism, but obligations of the manufacturers. More honesty and effort is certainly called for by manufacturers. It's rather unfair, but my biggest gripe is with Cessna. Yes, they make one of the safest planes, the 172. However, they haven't raised the bar in decades, even with being a number one seller. Shame on them. I expect Bob's practically home built brand to have less safety. Bob needs to be transparent about that (apologies to any actual manufacturer named Bob). I expect better from anyone selling 50 plus planes for year's.

Posted by: Eric Warren | September 13, 2012 7:01 PM    Report this comment

Eric, I hereby confer upon you universal Papal dispensation. Peace be with you. (Or at least a couple of cold beers.)

Posted by: Paul Bertorelli | September 13, 2012 7:45 PM    Report this comment

Paul, when was the last time you jumped? EFS

Posted by: Bradley Spatz | September 13, 2012 7:57 PM    Report this comment

Gentlemen, Pipistrel did comment on the article before it got posted but unfortunately 90% of the reply didnt get printed or mentioned ?? Pipistrel provided a qualified reply on accidents going back to 1995 and mentioned details on how the human head reacts in a crash etc, etc... I would like to see the full reply printed in the effort of having editorial fairness and also promote more discussion because it raises some important information.

Posted by: Michael Coates | September 14, 2012 4:07 AM    Report this comment

Extracts...... The cockpit design is made of Kevlar reinforced composites and the seat belts designed so that the head passes well below the main strut. I am 5 ft 9'' myself and have never head an issue bumping into any structure. We have had serious crashes because of pilot error, and even there – none of the occupants bumped into the spar which Mr Valldejuli claims to be »in front of his head«. What everybody forgets is that your head is »hinged« to the body at the bottom of the neck – and not on the forehead. Hence in an impact, the head goes DOWN and not forward (you can see this in car crashes as well – this is why airbags are coming from the steering wheel, which is well BELOW the eye (forehead) level, and not from the windshield somewhere).....It is common sense that you do not lean forward when the situation becomes an oh-shit moment! I do not know how the cockpit demonstration went for Mr Valldejuli, as I was not present, so I cannot directly comment on that. What is for fact is that »leaning forward before impact« is not our design principle behind cockpit safety

Posted by: Michael Coates | September 14, 2012 4:10 AM    Report this comment

Further, because the spar is in the location of where it is, it makes the cockpit MORE safe, because an impact into e.g. a tree branch will be stopped by the spar and not fly freely through the cockpit into someone. You have flown the Virus, you saw where the spar is relative to oneself. When comparing the Archer II to the Virus – ever wandered what happens when the aeroplane rolls over on ground. It is one of the most typical crashes, e.g. nosewheel brakes off then the nose dips into the ground. Archer has no roll cage (like Virus, Panthera, even Taurus in our case), but the occupants heads would simply be squashed. Is that what makes an aeroplane so great?

I am not saying our design is perfect, but there definitely was a lot of thought in its execution and keeping everybody safe. We have not had any deaths related to accident head trauma, and people were involved in ditching, even crashed into a mountainside in a white-out situation. In our view, we view our cockpit design safe, in fact, much safer than most aeroplanes. When strapped in, you are sorrounded by Kevlar reinforced element and energy absorbing zones from all sides, with the main spar protecting you from above (roll over), the A-pillars/spar cage (forward impact), undercarriage uni-element design (below) and collapsable fuselage ribs (behind).

Posted by: Michael Coates | September 14, 2012 4:11 AM    Report this comment

Further, because the spar is in the location of where it is, it makes the cockpit MORE safe, because an impact into e.g. a tree branch will be stopped by the spar and not fly freely through the cockpit into someone. You have flown the Virus, you saw where the spar is relative to oneself. When comparing the Archer II to the Virus – ever wandered what happens when the aeroplane rolls over on ground. It is one of the most typical crashes, e.g. nosewheel brakes off then the nose dips into the ground. Archer has no roll cage (like Virus, Panthera, even Taurus in our case), but the occupants heads would simply be squashed. Is that what makes an aeroplane so great?

Posted by: Michael Coates | September 14, 2012 4:12 AM    Report this comment

To put things into perspective: On thanking FAA and Piper for the crash tests – Crash test for small general aviation was imposed by the FAA with the »The Dynamic Crashworthiness Requirements« detailed in FAR23.562, first issued in August 1988 as part of the FAR-23 document. This was then further explored during the NASA/FAA AGATE program in mid-1990. My point here is that the Archer I (certified 8 July, 1975), which Mr Valledejuli references, was NOT even tested for Crashwortniess, despite his claims.

Posted by: Michael Coates | September 14, 2012 4:13 AM    Report this comment

I last jumped in 2009. A shoulder injury has made my return the sport iffy. We'll see, I guess. I miss it.

Posted by: Paul Bertorelli | September 14, 2012 5:00 AM    Report this comment

I hadn't heard that bit about Diamond before. I still like the Pipistrel. You can do things to minimise that kind of problem. My pet gripe is with bubble canopies that can leave you trapped. I think they're the best design for a "sporty" airframe but should always be rearward-sliding (or rearward "parallelogramming"*) to open and lockable in that open position. Grumman had no trouble designing them that way.

* - apologies to lovers of the English language.

Posted by: john hogan | September 14, 2012 6:38 AM    Report this comment

Interesting how we as humans tend to focus on what was said and assume the statement is correct i.e. "Mohandas Gandhi did not live until 140 years old how old was he when he died?" a true statement with a twist He was 79 when he died but the majority of people asked that question will think of plus minus 130 years.

Mr Valledejuli made a statement and everyone believed he said something true. Thank you Michael for putting us right.

David B Thurston wrote a book called "Design for Safety" in which he explains that although the technology available then (1980's) was sufficient to ensure safety the cost of applying those safety measures were the controlling factor. That measure is still in force today and that is why the GA aircraft is still what it is today nothing has changed and nothing will until it's no longer and the investors can say with hand on heart "Thank goodness we did not invest in GA.

Posted by: Bruce Savage | September 14, 2012 6:38 AM    Report this comment

Wow Paul I have really enjoyed your reporting and look forward to my emails From AVweb primarily because of you. But I'm dissapointed, why not let us see the full reply from Pipistrel to read and decide for ourselves??

Posted by: Dave Bowman | September 14, 2012 7:42 AM    Report this comment

Fiar enough, later this morning I'll post the full text of both.

Posted by: Paul Bertorelli | September 14, 2012 7:57 AM    Report this comment

Absent compliance withh standards, crashworthiness always is nothing more than a matter of opinion. If I build an "aircraft" out of steel-reinforced concrete, it not only will be crash-worthy, it will be crash-proof. Of course, it never actually will fly, but that would be a minor detail in the opinions of some.

In the absence of standards, how crashworthy is worthy? Ask 100 people; you'll get 110 opinions.

So, should there be standards?

Posted by: Thomas Yarsley | September 14, 2012 8:42 PM    Report this comment

There are standards for aircraft safety, i will try and get the details from the factory next week but they start with seatbelts, mounting strength, safety in the cockpit for sharp objects and so on... Drop test for undercarriage etc..

Posted by: Michael Coates | September 14, 2012 8:53 PM    Report this comment

Thanks to John A. Valldejuli for his observations and concerns, and Paul for acknowledging safety issues we all face and our postings with further interest. Crashworthiness is not just about the condition of the cockpit but the condition of the occupants after the accident. If I read the the LSA ASTM 2245 Standard Specification for Design and Performance of a Light Sport Airplane1, The 'Emergency Landing Specification is 3G's up, 9G's forward, 10G's for the engine. I did not find a down condition in the listing. This is very modest. Crashworthiness design methods are focused on slowing the body at G levels that do not cause internal injuries. This Suggests the body does Not hit anything hard during the process. That '56 chevy killed drivers hitting the immovable steel steering wheel and post along with the passenger hitting the windshield and steel dashboard. Today crush zones, seat belts, and air bags slow the passenger's body to below the fatal G load while the car is crushed but not the compartment.

Posted by: Philip Potts | September 15, 2012 5:52 PM    Report this comment

Clyde Cessna figured, maybe by accident, that a spring steel gear, strut mounted wings, and slow docile landing characteristics were the best configuration for the 150, 172, et al. Especially for a training aircraft that hits the ground at about 15 per 100,000 flt hr and a fatal rate that bests the industry. [Aircraft Now have access to parachutes which limit the impact speed and provide attitude control] I'm an engineer for 40 years and presently a safety officer; my observation is engineering often falls in love with their designs and they can miss some important issues if not scrutinized prior to production. Pre certification Testing helps but we all become the testing group once we own these new vehicles that meet the LSA standards. My Response to Pipistrel's Mr. Tine Tomazic is John A. Valldejuli's observation is sound; but flying any LSA does not meet the highest standard of crashworthiness.

Posted by: Philip Potts | September 15, 2012 5:52 PM    Report this comment

The 172 is no longer the industry leader in fatal per 100,000 being topped by the DA20 and DA40 with more docile handling, springy gear, and modern crash worthiness, and responsible choices that Cessna could make if they updated.. Also, many have said for years that normalizing the 172 stats for getting so many training hours (which are safer than average) puts it no better than several competitors. It's docile, it's THE most well known plane, and it's a death trap from the 40s if you actually crash it.

Posted by: Eric Warren | September 15, 2012 10:21 PM    Report this comment

Eric, the Cessnas--at least 172/182--don't seem too bad on crashworthiness. The 172's fatal rate is .45/100,000, compared to 1.2 for GA on the whole. If you could normalize it to cancel the training bias, what might it then be?

A way to do that is to look at the 182, which is predominantly owner flown and doesn't have much training bias. It's a little faster and a little heavier. The 182's fatal rate is .69/100,000--still considerably better than the industry average, but also twice the rate of the Diamond DA40.

One way of inferring crashworthiness is to compare overall rate to fatal rate and to look at the percentage of accidents that are fatal. The 172 has a somewhat elevated overall rate at 4.3, but a low fatal rate. The 182 has a lower overall rate (3.3) against a slightly higher fatal rate. For the 172, 10 percent of accidents are fatal, the lowest of any model, including Diamonds. The 182, at 21 percent fatal, is the next lowest. For comparison, the Cirrus SR20 is at 56 percent fatal, the SR22 at 45 percent fatal.

When I examined a dozen airplanes for comparative accidents rates, the 172 and 182 were in the top five for low accident rate. Not bad, really. As I've reported, the Cirrus airplanes finish in the middle, with the Cessna 206 and Mooney M20 series as the worst.

Posted by: Paul Bertorelli | September 16, 2012 5:41 AM    Report this comment

Paul B, I bow to your expertise and experience on the accident rate fiddling. However, I wonder what other factors play into both the accident rate and fatal rate.

I know from personal experience the 172 and 182 are both easy to fly but the 182 requires additional training for most pilots because of the large engine and extra weight and inertia. I wouldn't be surprised to learn the additional accidents are due at least in part to the extra weight and difficulty in handling.

Since the vast majority of accidents come from pilot error it seems the easier a model is to fly the less likely it is to have accidents. Another issue is the "Hot dog" factor where pilots perform maneuvers to show off rather than to get from point A to B. Perhaps the mundane appearance of the 172 and 182 attracts fewer pilots with this tendency than the slicker looking Mooneys and Bonanzas.

One last comment on crash worthiness. I remember reading some stuff many years ago about the likelihood of fire after a crash and how some simple check valves could prevent a lot of these deadly fires. I'm sure there are other simple and relatively inexpensive tricks manufacturers could include in their designs if they wanted better statistics.

Posted by: Paul Mulwitz | September 16, 2012 6:31 AM    Report this comment

Just looking at the LSA accidents. There have been a few with the CTLS but no one has been killed in one.When the plane crashes and rolls it seems only minor injuries

With the Pipistrels and LSAs there has also been a few accidents and people killed but I think there seems to be a lot more of the CTLS about hence it seems to be a safer plane.

Another aircraft that looks great on paper, not an LSA is the Liberty Xl, there seems to have been quite a few fatal crashes in them aslo, in an aircraft that is designed as a trainer. Judging by the numbers flying the LSa (CTLS ) seem safter than a part 23 aircraft.

Posted by: pat fitz | September 16, 2012 7:19 AM    Report this comment

Please read the NTSB reports before declaring one aircraft safer than the other. The unsafest thing in the air is the pilot not the plane. the problem for Pipistrel is that most of the aircraft are registered in the glider category, this means a vast majority of our customers have a medical issues that prohibit them from flying normal aircraft or LSA aircraft so they get a Pipistrel registered as a glider and they can self certify themselves as being medically fit for each flight. Unfortunately for Pipistrel this means we are probably going to see a few more accidents than we would like because of medical fitness of the pilots. In one instance we had an owner who had stints in his heart, he couldn't drive a car for two weeks so he decided to fly his plane two days after the operation.

Posted by: Michael Coates | September 16, 2012 8:03 AM    Report this comment

Paul, you're right--there are many factors piled up in an accident rate that are impossible to qualify or quantify. The only fair way to do it, given the limited data we have, is to let the raw numbers speak for themselves, without making excuses for one model and not for another. It's certainly fair to consider the mitigating circumstances because ultimately, you're the judge of relative safety based on the data you see. It's like the old joke about an airplane being perfectly safe if it just weren't for all the engine fires it had and the elevators coming loose.

Michael, as for self-cert being a factor, it may be. But it applies equally to the entire LSA segment, not just gliders. If you survey LSA manufacturers--and, as we have, pilots--you will find many of them flying without a medical. For all I know, it's most of them. Indeed, that's why they got into LSA in the first place, because they're worried about holding a medical.

As for Flight Design having a "few" accidents, I don't know if you'd call 35 a few or not. I wouldn't. But that's what the NTSB has on record for U.S. activity. There are about 350 FD airplanes on the U.S. registry, so 10 percent of the fleet has had accident involvement. That's quite a bit above average for certified airplanes. (It's about 3 percent for Cirrus and 2.5 for Cessna models since 1997, for instance.)

Posted by: Paul Bertorelli | September 16, 2012 9:07 AM    Report this comment

That's not to damn the FD models--or Pipistrel, either-- just merely noting the record. For all those FD accidents, there have been zero fatals, which is quite remarkable and suggests that despite a high accident rate, the airplane is quite crashworthy. This same relationship doesn't seem to apply to all models, certified or LSA. The Skycatcher is another model with few accidents and no fatals.

I'm developing some additional rate data to compare these airplanes on an accidents/hour basis. But that's only accident rate, not crashworthiness. The two aren't the same thing.

Posted by: Paul Bertorelli | September 16, 2012 9:10 AM    Report this comment

Hello Paul, it is very important that you understand the self certification for LSA versus gliders. LSA aircraft do not require you to have a medical but if you have had a medical at some stage and it was denied on renewal then you cannot fly and LSA aircraft. A lot of our customers are people who have lost their medical due to illness or old age. These people cannot fly LSA aircraft ever!. They can however fly a glider which you can fly if you have never had a medical or if you have lost your medical. This is a big difference between the two categories and is something that cannot be overlooked when you are doing your evaluations of what aircraft are the safest. A lot depends on the health of the pilot and their medical issues which could prohibit them from flying LSA aircraft.

Posted by: Michael Coates | September 16, 2012 9:11 AM    Report this comment

Is there evidence that self certification has caused an accident to due pilot incapacity?

Posted by: Dave Fisher | September 16, 2012 9:38 AM    Report this comment

Unfortunately yes

Posted by: Michael Coates | September 16, 2012 9:41 AM    Report this comment

How about some details on this, Michael. Is this a U.S. accident? Durango or Ray?

Posted by: Paul Bertorelli | September 16, 2012 9:57 AM    Report this comment

Sorry i am not going to report on individual accidents and people, remember others including family read these newsgroups as part of the grieving process looking for answers and i wont comment

Posted by: Michael Coates | September 16, 2012 10:01 AM    Report this comment

One factor with LSA which deserves the light of day is the problem of transition training. Since these planes all have the same configuration as one trainer or another (the 2 seat limit) many people mistakenly think they are as easy to fly as typical trainers. This simply isn't so.

I had a very nice Tecnam Echo for a couple of years and helped the new owner learn to fly it (even though I am not an instructor). He did OK in the two hours or so we worked together and then took off on a solo flight from the West coast to Pennsylvania. On his first day he had a hard landing in Utah and had to replace a tire (or some such repair). This probably wasn't reported as an accident but still helps to understand the fact that transition to some of the higher performance LSA designs is non-trivial. Perhaps this shows up in the accident statistics for non-fatal accidents more than you would get from part 23 planes which tend to be much more docile to fly.

Posted by: Paul Mulwitz | September 16, 2012 11:21 AM    Report this comment

Paul, Accident rates and crash worthiness are totally unrelated. Most Cessna models, 172 and 182, tend to hit the ground slow due to design and lack of thrust. That's good, but it hides the lack of modern crash worthiness that Diamond took advantage of. I believe the Corvalis, not designed by Cessna also has more crash worthiness. Are you saying Cessna, the biggest GA manufacturer, shouldn't be ashamed of not upgrading their product? Do you know the market advantage they have? It's stinky how the waltzed through the boomlet investing so little in new planes.

Last studies I saw comparing modern Mooneys with Cirrus had Mooney on top. Cirrus may be doing better now by improving training, fleet sales, changes to the plane, etc. Lumping the M20's together is misleading in the extreme. Some of them have wooden wings!

The Ovation and later have a lot of RLoC accidents which could be overcome with training, but even when Mooney was making them, they allowed that to be farmed out to a group I found to be mediocre. All that said, Mooneys have a steel safety cage, but it's also an old design with few upgrades, and they tend to hit beyond survivable velocities.

Posted by: Eric Warren | September 16, 2012 6:32 PM    Report this comment

"Last studies I saw comparing modern Mooneys with Cirrus had Mooney on top."

Whose studies are you referring to, Eric? I looked for this data, couldn't find it and spent a laborious month developing my own. The Mooneys I refer to are the modern long body models, which I compared directly to Cirrus and others for the same time frame.

The Mooney fatal rate is the highest of the group I studied, at 1.6 versus 1.2 for the GA average. Cirrus is at 1.5. In a message above, you called the 172 a deathtrap, yet you present no data to back that up.

Of all the airplanes reviewed, the 172 has the lowest percentage (10 percent) of accidents that are fatal, its overall rate is 4.3 and its fatal rate is .45, right behind the Diamond DA40.

Pray tell how this is a deathtrap? So no, Cessna should in no way be ashamed of its Skyhawk record. It's one of the safest airplanes in GA. Period.

If anything needs improvement safety wise, that would the 182's landing characteristics. They're awful, in my view.

The thing about crashworthiness is this: You can make fancy claims about steel cages and kevlar roll boxes all you want, but if the demonstrated record is crappy, you're good on theory, but lousy in practice. That's why this is so hard to judge. No good data.

Posted by: Paul Bertorelli | September 16, 2012 7:55 PM    Report this comment

Given the training and low-time pilot flying done in 172s, those stats are fan #@?! tastic! I still apologise in advance whenever I get in one although chances are it will take my ham fisted minIstrations in it's stride :-) They seem tinny compared to pipers but must have metal in the right places.

Posted by: john hogan | September 16, 2012 8:49 PM    Report this comment

Once again, rates and crash worthiness have no relationship. Agree or not?

Most of Cessna can be really proud of the good work of people who designed a great plane decades and decades ago. They may be fine people who do their jobs well, but they can certainly do better. Or, at least they could have back when they started shipping the 172S. Now, I can understand the unwillingness to replace or upgrade it.

The Mooney v Cirrus rates were discussed greatly about 6 or 7 years ago in several articles and quoted by Mooney a lot at the time. Cirrus was at the time being compared to the V-tail Beech experiences. I am really surprised you don't recall. Sad if Mooneys have been doing worse since. Totally spit balling, but I would bet second owners of the Mooneys are not getting proper training on the unique characteristics.

Still, I would put Mooney second in crashworthy behind the Columbia/Corvallis with Cirrus third among high performance planes. BRS undoubtedly helps the Cirrus rates, as does an excellent owners group and training resources. There is no data, so asking for it again won't prove your point, only that you are missing mine.

Posted by: Eric Warren | September 16, 2012 9:32 PM    Report this comment

"The Mooney v Cirrus rates were discussed greatly about 6 or 7 years ago in several articles and quoted by Mooney a lot at the time. "

Again, I am asking you to cite the specifics. Show us the actual data we can examine. Of all the manufacturers I have contacted, only Cirrus maintains--or at least will release--fleet hour data. I have confirmed their numbers independently with a high degree of confidence.

"rates and crashworthiness have no relationship." As I said above, that's true, but one can infer things about one from the other. If an airplane has a high rate, but a low fatal rate, it's reasonable to infer from this that's it has pretty good crashworthiness, absent any other data and despite what may appear to be true on the surface.

You're trying to make the claim that the 172 is a deathtrap based on your assessment of its antiquated construction and structure and that the Mooney must be much better because of its steel cage. Ok. Well show me the bodies. Where are these 172 deaths?

I have given you data here that shows in terms of real world survivability, the opposite is true. You say you would put Mooney second in crashworthiness behind the Columbia, yet you cite no information why you think this is true against data that suggests it is not. I see your point perfectly, Eric. It's just that you can't support it with fact.

Posted by: Paul Bertorelli | September 17, 2012 4:53 AM    Report this comment

Above, I got dinged on the opinion that LSAs don't have the crashworthiness of Part 23 airplanes. It's a fair criticism of an unsupported opinion. Could be as a fleet, they have the same numerical relationship as the 172 does. I have to grind through the numbers to find out. If anyone else is doing this, they're keeping quiet about it.

"BRS undoubtedly helps the Cirrus rates"

And you know this how? If you're not familiar with the risk homeostasis theory, read up on it. Even some people in the Cirrus community believe that the presence of BRS actually encourages pilots to take more risk, thus increasing the likelihood of an accident and having a negative effect on rates. No one knows if this is true. I certainly don't.

If you don't subscribe to risk homeostasis, BRS has zero impact on accident rate because once it's deployed, that's an accident. What it affects is survivability, which it greatly improves if deployed in time. I have the data on that, too, if you'd like to see it.

Posted by: Paul Bertorelli | September 17, 2012 5:03 AM    Report this comment

I am curious about the nature of accidents where BRS are deployed. I understand they are supposed to improve survival rates, but I have also heard of instances where there were fires on board where the parachute actually caused occupants to burn before reaching the ground.

Put differently, I wonder if BRS deployments are always helpful or at least neutral regarding fatalities.

Posted by: Paul Mulwitz | September 17, 2012 5:09 AM    Report this comment

"instances where fires on board...burned occupants"

Speaking of the Cirrus, only one of these. It was mid-air in which the aircraft ignited prior to impact. The BRS deployed, but it's not known if the occupants deployed it or the fire did. Absent the fire, it might have been survivable. ("Might" assumes the occupants weren't killed in the collision.)

Otherwise, there have been about 32 CAPS deployments, with another possible. Sixty one occupants been involved in these deployments, 43 survived without injury. Seven serious injuries as a result of sub-optimal deployment. Six fatalities associated with sub-optimal deployment.

At least 12 aircraft have been repaired and returned to service after CAPS deployment, something Cirrus never promised but which, nonetheless, has been the case.

Posted by: Paul Bertorelli | September 17, 2012 7:04 AM    Report this comment

Reading through the above I am again reminded of the words written by the late David Thurston someone I quoted above referring to the book he wrote called “Design for Safety”. In the preface he states “...certain types of accidents are really not so much the result of pilot error as they are the fault of poor design, poor flight instruction technique, inadequate air traffic control and communication procedures and questionable airport location.” He goes on to say “A control or procedure that does not exist cannot be improperly managed and this is particularly important during periods of extreme or unexpected emotional stress. The engine stopping, ice forming rapidly, running into severe clear-air-turbulence or an imbedded thunderstorm or having a complete electrical system failure instrument conditions will cause emotional stress regardless or anyone's flying time or years of piloting experience,” A brilliant book pity not many took any notice of what was said and this was back in 1980. Cont....

Posted by: Bruce Savage | September 17, 2012 7:05 AM    Report this comment

Cont... When I get into my Jaguar or modern car I am immediately surrounded by comfort and safety and I have had accidents in Jaguars before and left the crumpled steel unharmed can't say the same for the Morris Minor I had. When I get into the latest aircraft I feel that I have just sat down in a 1986 Land Rover. Is the lack of comfort conducive to pilot error? Possibly. The lack of comfort does not help to reduce emotional stress. But hey we are pilots and can take anything a few dying here and there is all in the name of flying.

I'm tired of been told that such and such accident happened and could have being avoided if the PILOT had done this or that. What rubbish. The accident was destined to happened the day he/she bought the aircraft.

Posted by: Bruce Savage | September 17, 2012 7:06 AM    Report this comment

I don't subscribe to 'Fate is the Hunter' as a risk management approach. The industries current thinking on risk management and investigation derives from the 1980's where the airline industry and FAA developed an understanding of Human Performance Levels and error rates. Actions were taken by the airlines and FAA to standardize procedures, communications, airport layouts, and aircraft cockpit configuration. These actions have been successful to the point where no fatal airline accidents occurred in the US or Europe last year. But I digress, Cirrus recently revealed that ~94 % of the accidents were human related errors not aircraft. These findings are consistent with other industry findings where 80 to 90% of accidents are a result of human performance conditions. Note: not all human performance errors are pilot causes.

Posted by: Philip Potts | September 17, 2012 8:18 AM    Report this comment

Sorry Philip I should have specified GA flying we pilots cannot afford the dog to bite us when we touch the controls

Posted by: Bruce Savage | September 17, 2012 8:29 AM    Report this comment

Eric, one other thought here. Perhaps it's not rational to think of crashworthiness as an absolute. In other words, although the 172 may have what you think is inherently poor crashworthiness, its crashworthiness is adequate for the flight profiles it performs, hence its exceptional safety and survivability record.

Ditto the Flight Design airplanes. They have a very high accident rate, but zero fatals. So the design's crashworthiness appears suitable to the airplane's use.

Cirrus, on the other hand, is the opposite. Only an average safety record, a higher than average fatal record and the highest percentage of accidents that are fatal.

Posted by: Paul Bertorelli | September 17, 2012 9:06 AM    Report this comment

Ouch, that 36 number for CTs seems high, until you see that it's spread over 8 years. Since the insurance carriers have mandated more transition training, hasn't the accident rate gone down noticably?

Posted by: tim greer | September 17, 2012 10:32 AM    Report this comment

Spread it out over flight hours, not years, Tim. That's the only apples-to-apples measure.

Posted by: Paul Bertorelli | September 17, 2012 10:52 AM    Report this comment

Paul, Force is equal to mass times velocity squared, you can't overcome that. You can't compare injury rates v overall rates on the existing data. I can't find you agreeing that rates and worthiness aren't related, and since you keep trying to show a relationship, I had to keep pointing it out.

I didn't say the 172 is a death trap. You take me out of context. I said, "... And it's a death trap from the 40s if you actually crash it." Cessna can rightly claim wisdom in not changing the crash avoidance qualities, but what have they ever done to upgrade the crash worthiness? Have they even upgraded the fuel lines yet? Flanged aluminum? Seriously?

There is no data on crash worthiness, as I said, you make no points asking for it. I think Aviation Consumer had an article on this years ago. They discussed the NASA tests, IIRC. I'm less sure on it being AC than I am the Mooney data.

I no longer work in aviation, don't have a good reason to find the citations, and since you don't know me well, won't take offense at you doubting my word. Your comments make me suspicious though that the Mooney hours may be under reported v Cirrus. Cont'd...

Posted by: Eric Warren | September 17, 2012 10:56 AM    Report this comment

...

I have debated BRS as much as anyone. I get hate from all sides because I won't drink any Kool-aid or accept worthless assumptions. The self selecting Darwin award pilot population argument is much worse than my crash worthiness argument for which you demand a study. Pound sand if you wish. BRS saved lives of people who we are free to interview and examine for foolishness. If even one of them wasn't foolish, it slews the numbers greatly.

On your final comments, you are close to the truth, you have to step away from the data and accept that you know things you can't prove. It's fair to question the wisdom of acting on those things, but not to ignore them. Grab an engineer and/or shop owner you think would be fair, and ask them to start listing things that should be updated for safety in the 172. Be less fair, grab someone from Diamond. Ask for simple things that wouldn't require a whole redesign (IMO a redesign that mostly just replaced the fuselage with composite would have been brilliant, and could make money even today with some structural changes to the biz model).

Part of the problem with GA is that it's roots are addicted to the 172. It won't change unless and until Cessna changes. If they don't man up (or give up) we will continue to wither.

Posted by: Eric Warren | September 17, 2012 10:57 AM    Report this comment

"I think Aviation Consumer had an article on this years ago. They discussed the NASA tests, IIRC."

Not in the last 25 years, that's for sure. No one has done the risk/hours study until we did it earlier this year.

If I can find a credible, neutral crash structures guy, I'll take you up on your challenge.

Posted by: Paul Bertorelli | September 17, 2012 11:23 AM    Report this comment

It wasn't risk hours, it was crash testing. I won't dig in boxes, but I will check my book shelf.

Posted by: Eric Warren | September 17, 2012 11:42 AM    Report this comment

This is an interesting and mostly intellectual string. The problem is that it remains inconclusive due to the obvious vast array of variables as well as limited data and analysis, mostly done by amateurs or professionals while on their lunch break (Paul B). Clearly, there are no easy answers but the quest is worth the effort.

On another point, although it is distressful to dig up dirt on accidents, I think we all have an obligation to encourage whatever learning can be gleaned. This extends to what might be considered by some as “disrespect for the dead”. Most of those wonderful dead people would be very happy if another life could be saved by exposing their mistakes.

And just to bring this down to earth (pun), take a look at this short video clip. Perhaps the aviation industry should be contracting with the Smart Car people regarding safety cage design. But this still won’t prevent g loads on human bodies in excess of what can be survived.

http://www.youtube.com/watch?v=9iKGfo1wmOM&feature=related

Posted by: James Herd | September 17, 2012 12:22 PM    Report this comment

It seems we can't post links here, but I'll try again:

http://www.youtube.com/watch?v=9iKGfo1wmOM&feature=related

If the link doesn't appear above then just go to YouTube and search on "smart car safety crash test". Click on the first item after the ads.

Posted by: James Herd | September 17, 2012 12:29 PM    Report this comment

You can post a link. Just paste it, remove the http and replace with www and it will work. It won't link directly, but will be pastable.

Posted by: Paul Bertorelli | September 17, 2012 12:34 PM    Report this comment

www.youtube.com/watch?v=n3bFhVvdlaI

Posted by: James Herd | September 17, 2012 1:15 PM    Report this comment

OUCH A 60 MPH Stop in 120Ft Takes 0.5 G's A 60 MPH Stop in 12 Ft Takes 5.0 G's A 60 MPH Stop in 1.2 Ft Takes 50.0 G's

If used! The Cirrus Parachute limits the downward velocity to about 25 ft per sec, something the seats are designed to absorb and you walk or swim away. No more math following. Other LSA's have similar chute devices. CFIT, into a mountain is not a design point for crashworthiness.

Posted by: Philip Potts | September 17, 2012 1:35 PM    Report this comment

Eric, what you're probably remembering is reporting done on a late 1970s to mid-1980s project by NASA testing hull crashworthiness. It included comparing composites to metal structures.

Piper donated some airplanes damaged during TS Agnes floods in 1972. We did the reporting somewhere around 1988.

Posted by: Paul Bertorelli | September 17, 2012 2:58 PM    Report this comment

Yep, that's the one. That's about all the crash worthiness data ever produced for GA. They didn't test a 172 in that? I'd be really, really surprised if there was much difference from the warrior/archer though.

Posted by: Eric Warren | September 17, 2012 3:26 PM    Report this comment

Up front, aviation is a dangerous activity which demands managing risk. As we all know, it is terribly unforgiving of bad decisions and external dangers such as bad weather. That said, crashworthiness and airworthiness are usually directly proportional ... i.e., a good flying airplane usually has a good crash record for a lot of technical reasons we could discuss ad nauseum. Insurance companies like C172 and PA28 airplanes for a reason (even tho they do still use flared aluminum fuel lines!). At AirVenture 2012, I talked with my insurance company and was surprised to find that they do NOT insure light sport hulls except in rare instances. Their loss stats tell them where their safest bets are. There are always going to be Darwin award pilots but the average 25 to 50 hour per year pilot that is interested in crashworthiness ought to start by talking with their insurance companies when deciding what to buy.

After reading all the 'hype' about the Virus earlier this year, I went over and took a look. It didn't take ME long to decide it wasn't for me. That spar IS a headknocker.

Some years ago, I had an old motorcycle helmet that I was going to toss so I put it on my C172 back seat. A few people laughed at it but my position was that IF I had time to put it on before a crash, I would. There are a lot of things a pilot could do to ensure their survival in a crash ... starting with the correct choice of airplane.

Posted by: Larry Stencel | September 17, 2012 4:11 PM    Report this comment

Larry, I don't know which insurance company is "Yours" but I have had two LSA's (one S-LSA, and one E-AB) and had no problems at all getting hull insurance. Perhaps the rates were higher than you might expect, but coverage was readily available in the market place.

In the case of my Zodiac XL I was able to get liability only for the first flight with me at the controls even though I had zero time in type. I was offered hull insurance but didn't like the premium. After the first year I added hull insurance - but changed insurance companies. Keep in mind the Zodiac XL has a history if multiple in flight breakups to make this story even more interesting. Mine had the design upgrade but at the time of my first flight there was very little industry experience with upgraded XLs.

Posted by: Paul Mulwitz | September 17, 2012 4:29 PM    Report this comment

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