Use Your Head
We study the rules, we memorize procedures, and we execute standardized practices in the hope of making our flights as safe as possible. Yet sometimes following checklists and procedures blindly to the letter can hinder that achievement, and a good pilot's job is to sort out the difference.
Before taking my private pilot students on their first "real" cross-country, I'd usually have them do a sort of rapid-fire tour of the local area airports by drawing a crisscrossing pattern of destinations for the student to plot checkpoints between, calculate winds and fuel burn, and get airport information. It was a great way of getting the navigation part down, throwing in a few landings, and leaving out some of the other confusing issues they'd face when we started to do more long-haul stuff (like filing, opening, and closing flight plans, and dealing with Class B and C airspace).
Of course, nothing ever goes perfectly well for some reason on training flights, and so I'd always throw in a few curveballs during the flight to test a student's ability to separate the minute details from the big picture. Somewhat intentionally, our home airport was a checkpoint almost directly between two of the small, intermediate airports, and toward the end of the flight period we'd usually find ourselves right about over home base. Right about when the student whipped out the E6B to run some numbers at our new checkpoint, I'd introduce a little "problem" into the mix.
Any student pilot knows I'm up to no good when I start grabbing at the throttle, and nearly every one of them had the same reaction as I started to pull the power back. After all, I'd let them know that they weren't flying solo unless they could demonstrate an engine failure procedure flawlessly. By the time the power was reduced to idle, they'd already be trimming for best glide and pantomiming the engine restart procedure. Except this time, I stopped the power reduction at about 2000 RPM, I locked down the throttle friction lock, and looked squarely at them and said, "You just heard a loud snap, and the power reduced to 2000 RPM. Let's say you tried to move it, and nothing happened. Your power is stuck where it is right now."
There was always a pause where he or she would look at me, somewhat dumbfounded as to what exactly I expected now. After all, we'd never covered the "loud bang and power set at constant setting" procedure in ground school, and up until that point most of the variables had been assessed prior to their appearance in the cockpit. After realizing the ball was solely in their court, the reactions varied as widely as the course deviations had been up until that point.
We, as pilots, like procedures. We like checklists, and memory items, and things we can do repeatedly and expect similar, if not identical, effects. The trouble is that some flights don't fall so into such easily categorized plots, and even the best flight instructors can't possibly train students for every possible contingency that could arise on a given flight.
This particular situation has happened on a number of occasions. Typically there's some sort of obstruction to the air intake, like a bird perhaps, or a severed throttle linkage. Whatever the reasons, it's not the sort of thing that checklists are generally written for. (Nevertheless, most students -- and I'm proud of them for it -- would start digging in the book at some point looking for a method of dealing with this issue.) Despite the importance that we place on following the book, this is a situation that requires good old-fashioned ingenuity and deductive reasoning.
A popular first attempt at solving the problem is to treat the issue as though it were a complete engine failure. Most students became quickly frustrated to learn that pitching to best glide didn't help much in this case. The power setting would hold altitude just fine, if not generate a slight climb. It would become readily apparent that we weren't going to get down very quickly at this rate. And unlike some other times, fiddling with the fuel selector or throwing on the carburetor heat scored no points today.
Get it Together
So what now? Well, the first step in this case is to assess what resources you have available, what you've lost, and what considerations should be made as a result.
In this case, we have an engine that's producing power, albeit at a reduced level. We'd always start these flights with plenty of fuel, so at the present moment it's not a pressing concern. We're flying over an airport that coincidentally has the longest runways for 50 miles in any direction.
It goes without saying that landing is the priority. Then again, with the number of cases where fuel exhaustion or carburetor ice kills pilots and destroys aircraft that passed several suitable airports by for some reason or another, perhaps it's worth talking about. It's always difficult to discern from the cockpit what exactly has caused a loud noise and a power reduction; and although the engine might keep right on pumping out power indefinitely, it might not.
Next up, we realize our primary method of controlling a variety of things -- like speed and rate of climb or descent -- is out of commission. Without direct control of the engine's output with the throttle, we've complicated what would normally be an easy descent to landing. It's important, however, to remember that we have a variety of ways of controlling drag, even when we can't control thrust. Most airplanes have flaps, and as it happens we're flying a Piper Warrior, which has that extra five degrees or so if you hold the lever back that increases drag noticeably (yet many people neglect to utilize it). Some others have gear that would have been retracted, and some others have speed brakes. We can always forward slip the aircraft to help lose altitude. And we still may have some control of the engine -- carburetor heat will reduce the power slightly, and moving the mixture control to cutoff will likely turn off the engine unless that cable has been affected as well.
We've still got electrical power and a working radio, so it's never a bad idea to call the flight school and ask to talk to a mechanic. If you're not sure who to call and not near home, I'd call the local control tower if there is one and ask for them to call the closest shop they know of and get a mechanic on the line with you. In the meantime, while we diagnose the problem, it's important to remain in the vicinity of our long runways and airport rescue personnel; if we weren't hovering over the top, we'd want to head toward the best thing available.
Once we've given up on fixing the problem, we get our limping bird slowed up, throw out some drag, and decide to head for the airport. It's important to plan ahead for what will not be a standard approach. Once the aircraft is over the runway, it will keep right on floating in ground effect until the runway is well behind us, so we need to plan to either land very flat or cut the power with the mixture over the runway. Obviously, going around is not really possible once you chop the fuel, so you need to be certain you're going to make it to the pavement without any difficulty before taking the plunge.
Though it seems simple on paper, it's not always so clear-cut in the real world. More than a few students struggled with how to deal with the circumstances. Some decided to keep going toward the airport we were originally heading toward, despite the fact that it has a tiny runway and is 30 miles away. Some decided to cut the power at altitude (which I would simulate by reducing the power the rest of the way with the throttle) and just make it a normal engine-out landing at the home airport, which unfortunately doesn't leave much room for error. One simply gave up and decided that there wasn't anything he could do to get the aircraft safely on the ground. Invulnerability, impulsivity, and resignation all come to mind.
"I Did Turn It Off!"
One of the luxuries of being a pilot for a paycheck is you get an all-expenses-paid trip to the simulator every so often, where some lucky guy or gal with an even more sadistic sense of humor than I have gets the opportunity to torture people like, well, me. Because the number of things that could break, malfunction, or just flat-out explode increases exponentially as the sophistication and size of the aircraft increases, you invariably run into a few situations every time you step into the box that challenge your ability to recall what exactly that switch on the right side of the panel actually does.
We were driving into our phantom airport after a round of engine failures and hydraulic issues when a new message popped onto the advisory monitor located in the center of the cockpit. It seemed one of our integrated computer systems -- the magic box that takes the data from the pitot tubes, static ports, flux gates, navigation equipment, and motion sensors and turns it into a fancy picture on a cathode ray tube -- was overheating.
I strained my memory for a procedure to execute when this occurs, but none came to mind. I called for my partner to get out our "Quick Reference Handbook" and run the procedure that should be associated with the message, which he promptly did.
In theory, that was all I was supposed to do. If there's a memory item associated with a message, there are certain things to execute. If not, there's a procedure in the book you do. My partner went over the checklist with me: It basically told you to pull the circuit breaker on the overhead panel for the associated computer. He did. The message remained.
My simulator instructor had that familiar wry smile that I'm sure my students knew well. What goes around comes around, I guess.
"Looks like that computer is starting to smoke," he said.
Though the procedure doesn't call for it, this is about the point I start to use four-letter words in the hope that a rapid vulgar prayer will make the yellow lettering go away. As usual, it didn't help.
As with the earlier situation with my students, the checklist had failed me. The computer was still getting power, and if this were real, we'd be dealing with a fire in the cockpit really soon. We couldn't shut the whole electrical system down, as we were plowing through the soup and wouldn't have any way to navigate.
My partner, as it turns out, is a lot smarter than me, and deduced not only that there was something else powering the unit, but managed to figure out what it was. As it's a pretty important piece of equipment, aircraft designers typically find a way of backing up power to the unit in case a bus somehow becomes isolated from the electrical distribution system. If we lost all the generators on the aircraft, we'd still need to navigate, and it would get awfully lonely in that cockpit with all the TV screens going blank.
There's a standby system. It's powered from the main aircraft batteries if all other power is lost; otherwise the bus is energized by the aircraft generators. The connection is downstream of the circuit breaker, too. The only way to isolate power from the computer is to remove the backup bus from the system, which is easily enough done by a switch flip on the overhead panel. My partner had already figured this out, and right about that time reached up and flipped that switch. A few moments later, the message went out.
My partner got a pat on the back, while my instructor mumbled something about how I should put my nose in the books more as my own brain caught up to what had just happened. The real lesson, though, is that a checklist is no substitute for knowing how the systems on the aircraft are put together.
"But I Followed the Checklist!"
I used to teach in flight training devices (FTD) quite a bit, which are fantastic mechanisms to use when teaching instrument procedures, and more importantly, emergency management. A classic scenario I'd set up for my students is that they had encountered some sort of electrical failure of the alternator. Most did pretty well when faced with the initial circumstances; most, if not all, recognized the bright light present in our aircraft (as with most aircraft) to signify a loss of electricity from the alternator. Most got out some sort of checklist and went through it, or at least tried to diagnose the problem and find a fix for it, whether it was by examining circuit breakers or recycling switches.
Most, however, were surprised when I didn't reward their efforts by making the bright light go away. Though somewhat puzzled as to what I was expecting, they typically decided that it was a bad situation to be in and needed to get on the ground pretty quickly. At their request, I'd give them vectors for the approach, and in an attempt to be good students, they go through the typical series of steps in preparation for landing, like turning on landing lights, fuel pumps, and putting the gear down.
Shortly after the gear handle swings, I'd get that evil smile my students became intimately familiar with and then fail the whole electric system -- radios, turn coordinator, GPS, and transponder. Their theoretical battery had just gone dead. Most throw in the towel at this point and ask what I could possibly expect them to do now.
It's a good question. Having myself briefly lost the entire electrical system due to a waterlogged bus, I know how frightening the thought can be of having no navigational capability in weather that is well below VFR. Fortunately, I managed to get something back by pulling circuit breakers and isolating the short, but if I hadn't had the good fortune of a battery that was still providing power, I'm not sure what I would have done.
Once again, although in a different set of circumstances, our protagonist to the story isn't doing anything technically wrong, from the standpoint of a checklist or operational procedure. I've never seen anything written to the contrary of the procedure that my students tended to follow in the situation, and most students I've examined for phase checks tell about the same story.
Yet our "by-the-book" mentality fails us again here. Having those shiny dual NAV/COMMs, the ADF, the landing lights, the GPS, the turn coordinator, the intercom, the Stormscope, the HSI, and any other goodies the previously good economy allowed your bird to be equipped with sucks power out of that little lead-acid battery at an alarming rate. Just watch that ammeter surge when you start moving objects that weigh dozens, if not hundreds, of pounds into the airstream, like gear or flaps, with electric or hydraulic motors. Some of that stuff should come off before diagnosis of the problem even begins, like the lights, the intercom, one of the NAV/COMMs, the ADF (you're not really going to shoot the NDB approach in this case, are you?), and the GPS, unless you need to shoot a GPS approach to get down. In that case, you should shut off the other NAV/COMM to save some juice, as well as the transponder, since ATC is going to lose sight of you anyhow. How will you get cleared for the approach? Who cares! This is an emergency situation, and you don't need a clearance nor should you be concerned about it in the first place. I assure you ATC will make sure there's nobody anywhere near your location until they work out what's going on.
The gear can free-fall or be manually actuated in most aircraft, often very simply. You don't need electric flaps to land, and if you manage to get them fully down right before the battery cries for mercy, you're faced with a difficult go-around circumstance, even if not faced with hard IMC.
The paint-by-numbers mentality of flying works in most cases and should be utilized as the backbone of the decisions you make in the cockpit. Yet the common sense you use to govern your daily life should still maintain veto power over the rules you've rehearsed in preparation for the ominous checkride. The important part is to analyze your own flying habits and find the procedures that can be made safer by a little intuition, experience, and intellect, and then put your new and improved procedure into practice. Remember, though airplanes can practically take off and land with computers nowadays, they still need pilots for the one thing that the computer lacks: common sense. Don't be afraid to take advantage of your own.