12.engine-out-procedures. Engine-Out Procedures (Multiengine Airplanes)
Engine failure in a multiengine airplane is a critical flight regime that demands immediate, well-rehearsed action. Unlike a single-engine airplane—where engine failure means a forced landing—a twin retains thrust on the operating engine, but that asymmetric thrust creates yaw, roll, and significant performance loss. The published single-engine climb performance of a typical light twin is often only 150–250 fpm at sea level, and that figure assumes the airplane is configured exactly per the AFM: gear up, inoperative propeller feathered, flaps retracted, cowl flaps as required, and the airplane held at VYSE (blue line) and VMC (red line) in mind.
Immediate Memory Items. When an engine fails after liftoff or in flight, the pilot's first actions are to maintain control and clean up the airplane. The standard flow, taught in nearly every AFH-aligned multiengine syllabus, is:
- Mixtures — FORWARD (full rich, or as appropriate for altitude)
- Propellers — FORWARD (high RPM)
- Throttles — FORWARD (maximum allowable power)
- Flaps — UP
- Landing gear — UP (when positive rate and runway is no longer usable)
- Identify the failed engine — "dead foot, dead engine" (the foot not pressing rudder corresponds to the failed side)
- Verify by retarding the throttle of the suspected failed engine — no change in yaw or performance confirms identification
- Feather the propeller of the failed engine
- Secure the failed engine per the AFM (mixture idle cutoff, mags off, fuel selector off, electrical/alternator off, cowl flap closed)
Pitch and Airspeed. Control of airspeed is paramount. After cleanup, pitch for VYSE (blue line)—the speed for best single-engine rate of climb. If the airplane will not maintain altitude at VYSE in the existing configuration and conditions (a real possibility at high density altitude or heavy weight), the pilot must accept a controlled descent at VYSE rather than allow the airspeed to decay toward VMC. Slowing below VYSE while attempting to hold altitude leads to drag rise, performance loss, and—if speed reaches VMC—loss of directional control.
Bank Angle and Rudder. A small bank of approximately 2° to 5° toward the operating engine, combined with rudder to keep the inclinometer ball deflected about one-half ball-width toward the operating engine, minimizes drag and yields published single-engine performance. Wings-level, ball-centered flight after an engine failure can cost more than 200 fpm of climb performance and increases VMC.
Engine Failure During Takeoff Roll. If a failure occurs before liftoff and the airplane is still on the runway, immediately close both throttles and abort. Use rudder, brakes, and—if necessary—differential braking to stay on the centerline.
Engine Failure After Liftoff, Gear Down. With the gear still down and the airplane below blue line, the AFH's general guidance is to land straight ahead, even if landing gear-down off-airport. The drag of an extended gear and a windmilling propeller usually exceeds the climb capability of a light twin, especially before the prop can be feathered.
Engine Failure After Liftoff, Gear Up, Above VYSE. Maintain directional control with rudder, identify–verify–feather, and climb at VYSE while leveling the wings 5° toward the live engine. Do not retract flaps below the AFM-specified safe altitude. Avoid turns into the dead engine until a safe altitude and airspeed are established.
Engine Failure En Route. At cruise altitude, time pressure is reduced. Establish VYSE if drift-down performance requires it, identify the failed engine, run the appropriate emergency checklist, and consider an air restart if the AFM permits and the cause is benign (e.g., fuel mismanagement). If a restart is not possible, secure the engine, declare an emergency as warranted, and divert to the nearest suitable airport. Plan the approach to permit a normal landing without configuring early; do not extend the gear or full flaps until the landing is assured, because a go-around on one engine with full flaps may be impossible.
Single-Engine Approach and Landing. Fly the pattern slightly higher and tighter than normal. Extend gear on final when the landing is assured. Use approach flaps only; full flaps are typically delayed until landing is guaranteed. Maintain VYSE until beginning the final descent, then transition to VREF or the AFM-recommended approach speed. Be prepared for the high pitch attitude required to arrest descent in the flare with reduced power.
Common Errors.
- Failure to maintain directional control with rudder
- Misidentification and shutdown of the operating engine
- Slowing below VYSE while attempting to hold altitude
- Failure to feather promptly, accepting unnecessary drag
- Banking the wrong direction or flying ball-centered
Proficiency in engine-out procedures is built through deliberate, repeated practice at altitude with a qualified instructor, simulating failures only by reducing power on one engine to zero thrust—never by actually shutting down an engine below a safe altitude.