Stomp hard on the rudder to control the yaw; force the pitch to stay slightly above the horizon, for blue line airspeed; bank into the good engine to combat the roll. Three seconds ago you were flying a twin… now you’re flying a single, with the working engine trying to twist your airplane over and into the ground.
What you do next — and the options you have open to you — depends on whether you’re near the ground, or at a reasonably safe altitude. We train and train for the dreaded engine failure on takeoff. Our training and evaluation makes it seems like engines never quit anywhere but during takeoff … or just after takeoff roll. The reality, though, is that most pilots who “lose an engine” in a multiengine airplanes experience the failure at altitude, in cruise flight. Why? Simply, because very little flight time happens in those few seconds close to the ground. You’re far more exposed to a failure in cruise, because that’s where you spend most of your flying time. Let’s look at things to consider with an engine failure at altitude…
ENGINE FAILURE… WHEN IT REALLY HAPPENS
“Modern” airplane engines are actually quite reliable. Statistics can’t prove the old saw that engines most frequently fail at the first power reduction, or because the gyroscopic forces of rotation break an already-weakened crankshaft. In fact, most engine failures are fuel related — a failed fuel delivery system (fuel pump, carburetor ice, etc.) or simply running out of fuel entirely. It happens so often we’ve created very specific terms for them — fuel starvation, describes the condition when there’s fuel somewhere on board but that tank’s not connected to the failed engine — fuel exhaustion, describes a situation where the airplane completely runs out of gas. Avoid fuel-related problems, and you’ll likely avoid engine failures altogether.
So, what about the engine failure in cruise — whether from fuel shortage, fuel delivery problems, or more catastrophic conditions? At altitude, consider:
- AIRPLANE CONTROL. As in all situations, fly the airplane. Your training should show that there’s a pitch attitude, a bank angle, and a rudder deflection that results in the best possible performance from your engine-out twin. In many cases, the “best possible performance” in an engine-out twin at most cruise altitudes — especially if it’s hot or your plane’s heavy — will mean the “least rate of descent.” In that case, “blue line” (Vyse) airspeed still results in the least total drag, and slowest rate of descent.
- TAKE YOUR TIME. Instructors of generations past taught thought, not haste, when responding to an emergency. Even if your cockpit’s fully digital, hold proper control inputs, take a breath, and think before you blindly act. So long as your elevator, ailerons and rudder stay where they belong you’ll be, at worst, in a slow controlled descent.
- DIVERT. Consider where a safe single-engine landing can be made and turn toward that site. Ask ATC for a vector. There are some special things to consider about recovery fields (and we’ll cover in a moment), but for now, be ready and act on your plan to divert.
- TROUBLESHOOT. Maintain control and keep aiming for your alternate, but if you have time try to restart the engine, do it. You should have your POH troubleshooting (sometimes called “restart” or “airstart”) procedure memorized, and practiced so that it’s automatic. Remember: there are three things an engine needs to run — fuel, air and ignition. If possible, switch fuel tanks, turn on an auxiliary fuel pump, or adjust the mixture. Does your airplane have an alternate air source or carburetor heat you can activate? Will changing the magneto switch position restart the engine?
- IDENTIFY, VERIFY, FEATHER. If manipulating the fuel, air and ignition systems doesn’t restart the engine, there’s nothing you can do from the pilot’s seat to fix the problem. Methodically reconfirm the failed engine using the “identification” and “verification” process you learned in multiengine training (“dead foot, dead engine” and throttle reduction being the most common techniques). Only then, feather the dead engine’s propeller.
- READJUST ATTITUDE. With the big reduction in drag brought on by feathering, the airplane will accelerate — and generate more drag. To continue to get “best possible performance” you’ll need to adjust pitch upward a few degrees to maintain “blue line” airspeed. You may even be able to hold altitude at higher-than-blue-line speeds — and it’s okay to do so!
- DECLARE AN EMERGENCY. There’s no down side to declaring an emergency if you’re engine has quit. At best, you’ll be Number One for a nice landing and have a great story for the next hangar session. At worst, rescue services will know exactly where you are and how to help.
- DO NOT ATTEMPT TO RESTART THE FEATHERED ENGINE — UNLESS you’re ABSOLUTELY SURE you know what’s wrong. In some designs a restart attempt that fails can prevent you from re-feathering the propeller — leaving you in a far ‘draggier’ configuration, with far less performance.
HOW TO PICK YOUR ALTERNATE
You’ve already aimed for a “recovery airport” — but what criteria did you use to select it? Considerations:
- Stay in (or get to) visual conditions if possible within a short flying time.
- Pick an airport with at least 5000 ft runway (there are a lot of them around, at least for U.S. readers). With a propeller feathered the airplane is far less “draggy.” You’ll float in the flare and take more distance to come to a stop once you’re on the ground. Add the natural tendency to fly a little fast under stress, and you’ll find that most light twins need more than 4000 feet to come to a stop with a feathered prop.
Experiment: With a qualified instructor — land with one engine at the “zero thrust” setting. Be ready to apply full power to both engines if needed to abort the landing, but if you make the landing, keep the engine in zero thrust through the landing roll. I’ve done this experiment with dozens of Barons pilots … and they learn just how much runway it takes to stop a twin with an engine shut down.
- Avoid crosswinds. Control authority is the issue in dealing with asymmetric thrust — and crosswinds require you use some of your control authority just to stay in a straight line, leaving less in reserve for any required maneuvering.
- Get vertical guidance. If you need to fly an instrument approach, pick an ILS. A second possibility is a Precision Approach Radar (PAR) approach at a military airfield, where the ground-based controllers monitor and advise of your descent rate. Unlike a non-precision approach, a vertical-guidance procedure provides a shallow descent to a point aligned with the runway. Once “visual,” use the VASI, PAPI, etc., to maintain glide path.
- Ignore irrelevant amenities like ground transportation or available maintenance facilities. Land at the nearest suitable airport regardless of the services available. You can work out those details once you’re safely on the ground.
SEALING THE DEAL
Beware of model-specific quirks. Watch out for “gotchas” associated with different airplane designs. For instance, some older twins (Piper Apaches, early Beech twins, etc.) only have one alternator or generator. Lose the engine on that side and you have an electrical problem, too. The same goes for hydraulic pumps (you need to manually pump down flaps and landing gear if the left engine dies in most Apaches), vacuum pumps, and other vital components. Study your POH and the airplane’s shop manuals for more information.
Land as normally as possible. Most light twins, once the dead engine is feathered and the gear and flaps are up, fly perfectly well on one engine at lower altitudes and at lighter-than-maximum weights. You may actually have to reduce power on the “good” engine to fly a normal landing approach. Put the gear down when you normally do, and go ahead and use flaps if you have excess airspeed. This is where your recent flight instruction and practice works for you. Most engine-failure accidents aren’t caused by loss of control at the point of engine failure — they happen during the approach to landing.
Approach go-arounds or missed approaches VERY cautiously. The airplane will take a lot of space to transition from a descent to a climb, will tend to lose airspeed rapidly — and may not even be able to climb out in high density altitudes or at heavy weights. Again, this is where recent, quality instruction and practice is paramount.
BOTTOM LINE: Intimacy with the Pilot’s Operating Handbook engine failure procedures, and good, recent experience in “realistic” engine failures (such as in a motion simulator one with at least a visual display and, as safely as possibly in the aircraft) is imperative. These methods are the only ways to learn the engine-out advantages a twin has over single-engine airplanes. Consider the time and money spent on quality, regular instruction as a mandatory part of owning and flying a multiengine airplane.