December 1, 2002
By Elizabeth A Tennyson
Every pilot trains for emergencies. We practice coping with them. We listen to — and may even tell — exaggerated stories about how we encountered them and cheated death. But as with much of our flying, we also tend to fall into a routine when it comes to preparing for in-flight emergencies.
Every candidate for the private pilot certificate can make an "emergency" landing after a simulated engine failure on downwind, and just about every examiner is going to ask for just such a demonstration. But we all know that engines don't conveniently fail when we're abeam the numbers. And engine failures are only one type of emergency that we might encounter.
Let's assume that we have all kept up the skills we learned as apprentice pilots and can make that engine-out landing from downwind, put our powerless airplane down in a field or on a road, know the correct procedure for coping with an electrical fire, and have the first few items on each of our aircraft's emergency checklists memorized. That's a good start, but there's plenty more to consider — most of which our standard training and normal flying has not prepared us for.
The fact is that emergencies are inherently unpredictable. That's just one reason why it's a good idea to spend some time thinking about the unthinkable. Control failures are one type of emergency that don't crop up in the average private or commercial training curriculum, but they do happen in real life as the pilot of a Cirrus SR22 discovered in October (see " Pilot Briefing: To Pull or Not to Pull the Chute," page 58). He successfully deployed his airplane's parachute and floated to a landing after an aileron failure. Of course, most of us don't fly parachute-equipped aircraft, so we need to have another plan of action.
Just how common are control-surface failures? A search of the NTSB database turned up an average of about 11 general aviation accidents each year caused by control failures. Because only those failures with outcomes serious enough to require NTSB involvement are included, it's impossible to know how many similar incidents ended relatively uneventfully.
But Rich Stowell, whose California-based Emergency Maneuver Training program ( www.richstowell.com) has prepared hundreds of pilots for this kind of emergency, believes that the maxim used in industrial accident prevention may hold true for general aviation. If so, only about one in 331 hazardous incidents of the same type results in an accident, implying that there are somewhere in the neighborhood of 3,600 general aviation control-surface failures each year. The good news is that these types of failures are highly survivable, if you know what to do. The better news is that there are plenty of opportunities to improve your odds.
The most common control failures — and among the most dangerous — are elevator failures. That's why Stowell teaches his emergency-maneuver students how to handle them — and he knows the techniques work because he has been forced to practice what he preaches.
Stowell and a student, who happened to be an airline pilot, were practicing aerobatics when they discovered Phat they had very little elevator authority. While there was some pitch control in the stick, it took large control movements to produce a small, delayed elevator response. Taking advantage of his student's airline training, Stowell employed crew resource management techniques to divide the workload — the student used the trim control to move the elevator while Stowell used the throttle to manage power. Between them they guided the airplane to an uneventful landing. Once on the ground they discovered that five of the seven strands making up the elevator cable had been severed and the remaining two were frayed.
This kind of elevator failure doesn't have to be a crisis, as Stowell's experience demonstrates. But if the airplane is out of trim when the elevator fails, you have a bigger problem. That's just one reason why it's important to keep the airplane trimmed throughout every flight, according to Don Wylie of Aviation Safety Training, a division of Houston-based Texas Air Aces ( www.aviationsafetytraining.com). Elevator failures are most often the result of a broken cable, which means that you may maintain some elevator authority through use of trim. Practicing controlling attitude using only pitch trim is a good way to get a feel for how your airplane might respond in the event of an elevator failure.
The second most common control failure is a stuck throttle — and it's usually stuck wide open. What do you do when you're barreling along at top speed and you lose your throttle control? Slow down, of course.
And believe it or not, that's pretty easy to do, says Wylie, whose years of flying fighter jets and teaching advanced maneuvering to civilian pilots aren't the only reasons he's an expert. He's also experienced a stuck throttle — twice. Slowing down, he says, is often a matter of climbing to trade altitude for airspeed. Once the airplane is within gear and flap operating limits, deploy them and anything else your particular aircraft might have that will create drag and slow you down. Then it's a matter of returning to aviation's roots and controlling power with the mixture — once the only power control on airplanes.
Wylie, who was flying with a trainee during one stuck-throttle incident, says the other pilot's eyes got so big he "looked like a tree full of owls." Wylie took the controls of the Cessna 182RG, climbed steeply to slow down, put out the flaps and gear, and used mixture to control power. "When I got over the numbers, I pulled the power off entirely," he explains. The result was a normal landing despite an abnormal approach.
Imagine that you're leaving the pattern en route to your favorite $100-hamburger joint. But when you try to transition to wings level after turning on course, you realize that the ailerons are stuck. Release the rudder you held in the turn and you're skidding. Keep the rudder in and you just keep turning. Uh-oh!
You're experiencing the third most common type of control failure. But is it an emergency? That depends entirely on what you do next. In fact, stuck ailerons are one of the easiest control failures to handle, provided you know what to do. And let's face it, sitting on the ground is the time to figure that out because if you haven't thought about it before it happens you may not be in any mental condition to rationally consider your options.
Stowell has had firsthand experience with this one, too. During one instructional flight in an American Champion Decathlon, Stowell and a trainee were working through unusual attitude recoveries and were in a 90-degree left bank when the ailerons stuck. "I had virtually full left aileron but only about 10 percent of right aileron," he recalls.
Rather than try to push through the obstacle, possibly compromising the integrity of the airframe and creating an even more serious condition, Stowell transitioned to a nice, stable slip by adding right rudder. In situations like this, adding power can preserve altitude and, with practice, you can steer yourself anywhere in a slip, he says. You'll need to turn to get yourself into the pattern and lined up for a landing, so make sure you turn in the direction of your slip. In Stowell's case "it was left traffic all the way!" The obstruction affecting the ailerons, incidentally, turned out to be a rogue screw that had become wedged in a bellcrank.
If you ever find yourself in a similar situation, take advantage of any wind by choosing a runway that allows you to land with your upwind wing down as you would in a normal crosswind landing. In this case, the wind can help you stay aligned with the runway centerline all the way through touchdown and rollout. With some practice and a clear sense of how to respond, you, like Stowell, can celebrate an uneventful landing.
Based on the NTSB database, flap problems tie for the number-three spot on the list of common control failures. Often, flaps simply fail to deploy, which should be no big deal if you've kept up with your no-flap landing practice. Split or asymmetrical flaps are a little more unusual and a lot more serious. That's because pilots typically have the "wrong" response to the rolling motion that results. As the airplane starts to roll, most pilots instinctively try to correct with aileron. Before they realize what's happening, they may be cross-controlled and on the way to a spin. Because flaps are usually activated close to the ground, there's little or no time to recover.
Wylie advises his students to keep one hand on the flap control until they know the flaps are where they're supposed to be. "Because if your hand comes off the flap lever and they split and the airplane starts to roll, you're not going to go back to that flap handle. If you just move on to ailerons, that can be deadly," he warns. Instead, the pilot's first response should be to put the flaps back up, which often solves the problem.
Stuck rudders, simultaneous aileron and elevator failures, and trim failures round off the list of common control problems.
When the rudder becomes stuck in the fully deflected position, the solution is the same as when the ailerons become stuck — a stable slip that will let you fly right back to the runway and make a straightforward crosswind landing.
A combination aileron and elevator failure means it's time to let go of the yoke and work those rudders. Wylie recommends that all pilots practice flying with their hands on their knees. You should be able to direct the airplane any way that you want it to go just using rudder and pitch trim, he explains.
Finally, trim failures generally can be overcome with elevator, although the exercise may be exhausting as you muscle the airplane into the desired attitude.
Being ready for a control failure or any other type of emergency requires a combination of the right mindset and the right training. Both Stowell and Wylie say that the first step in preventing a control failure-induced accident or incident is taking preflight seriously. Really check the controls to make sure that they move freely and in the proper direction. Listen and feel for anything unusual such as binding or scraping, and be sure there's nothing rolling around in the cockpit that could jam the controls — everything from a loose shotgun shell to a misplaced briefcase has jammed aircraft flight controls. Put down the flaps and, if they're electrically actuated, listen to the motor as you do. If the flap motor is struggling on the ground, it's likely to have real problems when it must overcome the aerodynamic pressure of the relative wind.
If you do have a control failure, don't panic. Do fly the airplane. Yes, it's a cliché, but it's become a cliché for a reason — it works. Stowell takes this idea one step further, saying there's a three-prong strategy pilots should adopt when something goes wrong in the cockpit:
Often the instinctive reaction is the wrong one. Taking a moment to assess the situation and consciously choose a course of action, instead of responding emotionally, can be lifesaving.
It's equally important that you approach each flight with the idea that something could go wrong. "When I take off, I assume I'm going to have to abort. If you put yourself in that mind state, you're ready for things to happen," says Wylie. He advises pilots to use the quiet moments during flight to ask themselves the what-if questions — where would I put down if my engine failed? What would I do if my rudder jammed?
It's also a good idea to get some specialized training, and then practice what you've learned. That means spending time in the practice area working on flying in a controlled slip, flying with your hands on your knees, and using pitch trim instead of the yoke to control the elevator. Emergency skills are perishable, and using them is the only way to be sure they'll be there when you need them.
E-mail the author at firstname.lastname@example.org.
A control failure can be one of the most terrifying things for pilots. We spend so much time learning to be in control and so little time learning to function while slightly out of control. To simulate these situations I flew with a safety pilot in a Piper Archer. While some of the simulations we practiced could not happen, mechanically speaking, in such an aircraft, we tried to create some generic situations that apply to a range of airplanes.
It's one thing if the failure occurs on a sunny day with no wind or turbulence — the sort of day we chose for our test flight — but it's another if it happens during instrument conditions. My safety pilot, an aerobatics instructor, pressed the rudder to the floor with his size-12 shoe and suddenly we had what seemed like a stuck control surface. I pretended that controllers were vectoring us onto an ILS approach. Once the localizer needle started to swing I used left aileron to put it into a slip and flew.the approach as published, only at an extreme angle. I also kept the speed high, more than 100 knots, to keep from stalling and spinning in the cross-controlled configuration. A slightly more rapid descent, of course, was required to stay on glideslope.
Once stabilized, the approach was relatively normal. But had this been a real-life scenario, things could have been vastly different. I can only imagine the sudden confusion when the airplane goes sideways. And if your attention gets drawn away from the needles only for a split second, it's easy to blow right through the localizer. Then what? Talk about a crazy missed approach.
While we may have looked silly to folks on the ground on a no-crosswind day, an interesting thought came to mind. Gee, I've got to land like this. Sideways. Not wanting to destroy the landing gear, we broke off the approach at a safe altitude. I would not recommend practicing this maneuver close to the ground, certainly if you don't understand spin recovery. It has the potential to be every bit as lethal as the real thing. Give yourself and your experienced safety pilot several thousand feet of altitude and try holding a constant heading or following a road instead of a localizer.
To simulate the aileron failure, we climbed above 3,000 feet agl. With my safety pilot deflecting aileron to the right, I quickly ran out of enough rudder to compensate. Sensing an ugly situation developing, we neutralized the controls and flew more conservatively. Even with partial aileron deflection, it may take all the rudder you have just to hold a heading — forget turning to the left. I followed a GPS course on a moving map to get a feel for the airplane on the way back to the airport.
To simulate an iced-up airplane where we didn't know the stall speed, we followed the manufacturer's recommendations and made a no-flap landing between 70 and 80 kt. Nothing unusual there, aside from the longer ground roll. Some airplanes don't even have flaps.
We also failed the stabilator by having my safety pilot put his hands around the control column between the yoke and the instrument panel to simulate an elevator problem on most aircraft. Of all the maneuvers this was the least unsettling, thanks to the calm conditions. Massive turbulence would have upset more than the Archer.
We flew a normal pattern and I pulled a notch of flaps at pattern altitude to see how much the nose would rise. I quickly ran out of trim to compensate and the throttle became my fast friend. With a slight reduction in power, the airplane was back on track. To keep from destabilizing the airplane closer to the ground, I stayed off the flaps and used power and trim to bring us in.
OK. Lessons learned. I'll take back full use of the controls now. — Nathan A. Ferguson
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