FergWorld : Articles : Your Multi-Engine Rating
By Ryan Ferguson
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You'll learn how to fly the airplane around the pattern on one engine. Your instructor will "fail" an engine on your climbout (usually above a safe 500 ft. AGL). You'll learn the procedure you'll follow whenever this occurs:
- Mixtures full rich
- Props high RPM
- Throttles full forward (get full power from your good engine, whichever it may be)
- Flaps up
- Gear up (remove drag)
- Fuel pumps on (you might have had an engine-driven pump failure which you might immediately correct by activating the fuel pumps)
- Identify the bad engine by rudder pressure (dead leg, dead engine)
- Verify the bad engine by retarding the suspected throttle
- Feather the inoperative engine's prop
As a multi-engine student, you will start mumbling this mantra over and over, drawing strange glances from passers-by as your hands engage imaginary throttle quadrants and flight controls. You'll also learn how bank slightly into the good engine and try to fly 'uncoordinated' insofar as the ball in your turn coordinator goes. If you point the aircraft straight forward through the air, even at a slight bank angle, you'll prevent the considerable drag caused by the side of the fuselage skidding through the air. Therefore, you'll want the ball to be slightly out of its cage instead of centered. Your MEI will explain in detail.
New to the world of feathering props? You probably already know that feathering a prop means adjusting its pitch angle so that it bites cleanly into the wind with the least possible drag. But perhaps you didn't know that an unfeathered, windmilling prop accounts for a huge amount of drag. The effect is that of a large, solid, flat plate being mounted to the propeller hub. It's usually more drag than full flaps and extended landing gear combined! Making matters worse, since it's on one side of the airplane, it's going to really exacerbate our asymmetric thrust problem. That's why feathering the prop, post-haste, is a necessity when we lose an engine near the ground. It is also critical for maximizing single engine cruise performance.
When you do this in the aircraft, you'll also note how climb performance is significantly reduced – and not by 50% as you'd expect (after all, lose one of two engines and you'll lose half the performance, right?). In reality, you're going to lose approximately 80% of your climb performance with one engine inoperative. Don't count on being able to climb with a dead engine – the FAA does not require light twins to have single-engine climb capability. That's why you'll find accelerate-stop performance charts in your light twin POH, but no accelerate-go charts. Oh, yeah, you're not familiar with those yet – but by the time you take your checkride, you will be.
Weight and balance is as critical in a twin as it is in any other airplane. However, since you're always faced with the possibility of having to find an airfield on a single engine, you'll want to restrict the amount of fuel you carry. Be able to make your intended flight with a safe amount in reserve – carry no more, no less. (I always carry at least one hour reserve despite the FAA's more meager requirements.) Too much fuel will be dead weight in an airplane struggling to maintain altitude.
More training: single engine landings. Vmc demos – this is where the windmilling prop's drag makes itself especially evident. Your instructor might have you do drag demos, where you compare the aircraft's rate-of-climb in various configurations (gear down, flaps extended, etc.) Engine failures both on the initial roll, and on the climbout. Engine failures enroute. You'll learn how to shut down, secure and restart an engine (yes, intentionally shut down an engine in flight!) Like I said, it's all about flying single-engine. And it's actually pretty fun.
It is very satisfying to fly a multi-engine aircraft. The systems are more complex, the plane is more challenging to fly, and there is definitely a sense of achievement involved in mastering the skills necessary to be safe. Be forewarned, however, that complacency can set in after the instructor hops out of the right seat. Plan for at least yearly recurrent training in a light twin. Expect an engine failure on every takeoff, and be pleasantly surprised when you climb safely to altitude. Enjoy the sense of security you'll have when flying at night, over terrain or in instrument weather conditions. Most importantly, if you can afford it, do take the plunge – you'll be a better, and safer, pilot for having done so.
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