Chapter 12—Transition to Multiengine Airplanes
Table of Contents
Terms and Definitions
Operation of Systems
Flight Director / Autopilot
Alternator / Generator
Nose Baggage Compartment
Anti-Icing / Deicing
Performance and Limitations
Weight and Balance
Normal and Crosswind Takeoff and Climb
Level Off and Cruise
Normal Approach and Landing
Crosswind Approach and Landing
Short-Field Takeoff and Climb
Short-Field Approach and Landing
Engine Failure After Lift-Off
Engine Failure During Flight
Engine Inoperative Approach Landing
Engine Inoperative Flight Principles
Power-Off Stalls (Approach and Landing)
Power-On Stalls (Takeoff and Departure)
Engine Inoperative—Loss of Directional Control Demonstration
Multiengine Training Considerations
ENGINE FAILURE AFTER LIFT-OFF
A takeoff or go-around is the most critical time to suffer an engine failure. The airplane will be slow, close to the ground, and may even have landing gear and flaps extended. Altitude and time will be minimal. Until feathered, the propeller of the failed engine will be windmilling, producing a great deal of drag and yawing tendency. Airplane climb performance will be marginal or even non-existent, and obstructions may lie ahead. Add the element of surprise and the need for a plan of action before every takeoff is obvious.
With loss of an engine, it is paramount to maintain airplane control and comply with the manufacturer’s recommended emergency procedures. Complete failure of one engine shortly after takeoff can be broadly categorized into one of three following scenarios.
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Figure 12-11. Engine failure on takeoff, landing gear down.
If Engine Failure Occurs at or Before Lift-off, Abort the Takeoff.
If Failure of Engine Occurs After Lift-off:
Analysis of engine failures on takeoff reveals a very high success rate of off-airport engine inoperative landings when the airplane is landed under control. Analysis also reveals a very high fatality rate in stall- spin accidents when the pilot attempts flight beyond the performance capability of the airplane.
As mentioned previously, if the airplane’s landing gear retraction mechanism is dependent upon hydraulic pressure from a certain engine-driven pump, failure of that engine can mean a loss of hundreds of feet of altitude as the pilot either windmills the engine to provide hydraulic pressure to raise the gear or raises it manually with a backup pump.
CONTROL— The first consideration following engine failure during takeoff is control of the airplane. Upon detecting an engine failure, aileron should be used to bank the airplane and rudder pressure applied, aggressively if necessary, to counteract the yaw and roll from asymmetrical thrust. The control forces, particularly on the rudder, may be high. The pitch attitude for VYSE will have to be lowered from that of VY.
Figure 12-12. Engine failure on takeoff, inadequate climb performance.
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Figure 12-13. Landing gear up—adequate climb performance.
At least 5° of bank should be used, if necessary, to stop the yaw and maintain directional control. This initial bank input is held only momentarily, just long enough to establish or ensure directional control. Climb performance suffers when bank angles exceed approximately 2 or 3°, but obtaining and maintaining VYSE and directional control are paramount. Trim should be adjusted to lower the control forces.
• CONFIGURATION—The memory items from the “engine failure after takeoff” checklist [Figure 12-14] should be promptly executed to configure the airplane for climb. The specific procedures to follow will be found in the AFM/POH and checklist for the particular airplane.
Most will direct the pilot to assume VYSE, set takeoff power, retract the flaps and landing gear, identify, verify, and feather the failed engine. (On some airplanes, the landing gear is to be retracted before the flaps.) The “identify” step is for the pilot to initially identify the failed engine. Confirmation on the engine gauges may or may not be possible, depending upon the failure mode. Identification should be primarily through the control inputs required to maintain straight flight, not the engine gauges. The “verify” step directs the pilot to retard the throttle of the engine thought to have failed. No change in performance when the suspected throttle is retarded is verification that the correct engine has been identified as failed. The corresponding propeller control should be brought fully aft to feather the engine.
Figure 12-14.Typical “engine failure after takeoff”emergency checklist.
• CLIMB—As soon as directional control is established and the airplane configured for climb, the bank angle should be reduced to that producing best climb performance. Without specific guidance for zero sideslip, a bank of 2° and one-third to one-half ball deflection on the slip/skid indicator is suggested. VYSE is maintained with pitch control. As turning flight reduces climb performance, climb should be made straight ahead, or with shallow turns to avoid obstacles, to an altitude of at least 400 feet AGL before attempting a return to the airport.
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• CHECKLIST—Having accomplished the memory items from the “engine failure after takeoff” checklist, the printed copy should be reviewed as time permits. The “securing failed engine” checklist [Figure 12-15] should then be accomplished. Unless the pilot suspects an engine fire, the remaining items should be accomplished deliberately and without undue haste. Airplane control should never be sacrificed to execute the remaining checklists. The priority items have already been accomplished from memory.
Figure 12-15. Typical “securing failed engine” emergency checklist.
Other than closing the cowl flap of the failed engine, none of these items, if left undone, adversely affects airplane climb performance. There is a distinct possibility of actuating an incorrect switch or control if the procedure is rushed. The pilot should concentrate on flying the airplane and extracting maximum performance. If ATC facilities are available, an emergency should be declared.
The memory items in the “engine failure after takeoff” checklist may be redundant with the airplane’s existing configuration. For example, in the third takeoff scenario, the gear and flaps were assumed to already be retracted, yet the memory items included gear and flaps. This is not an oversight. The purpose of the memory items is to either initiate the appropriate action or to confirm that a condition exists. Action on each item may not be required in all cases. The memory items also apply to more than one circumstance. In an engine failure from a go-around, for example, the landing gear and flaps would likely be extended when the failure occurred.
The three preceding takeoff scenarios all include the landing gear as a key element in the decision to land or continue. With the landing gear selector in the DOWN position, for example, continued takeoff and climb is not recommended. This situation, however, is not justification to retract the landing gear the moment the airplane lifts off the surface on takeoff as a normal procedure. The landing gear should remain selected down as long as there is usable runway or overrun available to land on. The use of wing flaps for takeoff virtually eliminates the likelihood of a single-engine climb until the flaps are retracted.
There are two time-tested memory aids the pilot may find useful in dealing with engine-out scenarios. The first, “Dead foot–dead engine” is used to assist in identifying the failed engine. Depending on the failure mode, the pilot won’t be able to consistently identify the failed engine in a timely manner from the engine gauges. In maintaining directional control, however, rudder pressure will be exerted on the side (left or right) of the airplane with the operating engine. Thus, the “dead foot” is on the same side as the “dead engine.” Variations on this saying include “Idle foot–idle engine” and “Working foot–working engine.”
The second memory aid has to do with climb performance. The phrase “Raise the dead” is a reminder that the best climb performance is obtained with a very shallow bank, about 2° toward the operating engine. Therefore, the inoperative, or “dead” engine should be “raised” with a very slight bank.
Not all engine power losses are complete failures. Sometimes the failure mode is such that partial power may be available. If there is a performance loss when the throttle of the affected engine is retarded, the pilot should consider allowing it to run until altitude and airspeed permit safe single-engine flight, if this can be done without compromising safety. Attempts to save a malfunctioning engine can lead to a loss of the entire airplane.