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 cert ain
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.
Landing Gear Control Selected Up, Single-Engine Climb Performance Adequate
If the single-engine rate of climb is adequate, the procedures for continued flight should be followed. [Figure 13-20] There are four
areas of concern: control, configuration, climb, and checklist.
Figure 13-20. Landing gear up—adequate climb performance.
Control
The first consideration following engine failure during takeoff is to maintain control of the airplane. Maintaining directional control
with prompt and often aggressive rudder application and STOPPING THE YAW is critical to the safety of flight. Ensure that
airspeed stays above V MC. If the yaw cannot be controlled with full rudder applied, reducing thrust on the operative engine is the
only alternative. Attempting to correct the roll with aileron without first applying rudder increases drag and adverse yaw and further
degrades directional control. After rudder is applied to stop the yaw, a slight amount of aileron should be used to bank the airplane
toward the operative engine. This is the most efficient way to control the aircraft, minimize drag, and gain the most
performance. Control forces, particularly on the rudder, may be high. The pitch attitude for V YSE has to be lowered from that of V Y.
At least 5° and a maximum of 10° of bank toward the operative engine should be used initially 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 V YSE 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 should be promptly executed to configure the airplane for climb.
[Figure 13-21] The specific procedures to follow are found in the AFM/POH and checklist for the particular airplane. Most direct the
pilot to assume V YSE, 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 13-21. 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 toward the operative engine is suggested. V YSE 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 4 00 feet
AGL before attempting a return to the airport.
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 should then be accomplished. [Figure 13-22] 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 13-22. Typical “securing failed engine” emergency checklist.
Other than closing the cowl flap of the failed engine, none of these items, if left undone, adversely affect 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 an ATC facility is 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 will not be able to consistently
identify the failed engine in a timely manner from the engine gauges. In maintaining directional control, however, rudder pressure is
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 shou ld be
“raised” with a very slight bank.
Not all engine failures result in complete power loss. If there is a performance loss when the throttle of the affected engine is retarded,
some power is still available. In this case, the pilot may consider allowing the engine to run until the airplane reaches a safe altitude
and airspeed for single-engine flight. While shutdown of a malfunctioning engine may prevent additional damage to the engine in
certain circumstances, shutting down an engine that can still produce partial power may increase risk for an accident.
Engine Failure During Flight
Engine failures well above the ground are handled differently than those occurring at lower speeds and altitudes. Cruise airspeed
allows better airplane control and altitude, which may permit time for a possible diagnosis and remedy of the failure.
Maintaining airplane control, however, is still paramount. Airplanes have been lost at altitude due to apparent fixation on the
engine problem to the detriment of flying the airplane.
Not all engine failures or malfunctions are catastrophic in nature (catastrophic meaning a major mechanical failure that damages the
engine and precludes further engine operation). Many cases of power loss are related to fuel starvation, where restoration of
power
may be made with the selection of another tank. An orderly inventory of gauges and switches may reveal the problem.
Carburetor heat or alternate air can be selected. The affected engine may run smoothly on just one magneto or at a lower power
setting. Altering the mixture may help. If fuel vapor formation is suspected, fuel boost pump operation may be used to eliminate
flow and pressure fluctuations.
Although it is a natural desire among pilots to save an ailing engine with a precautionary shutdown, the engine should be left running
if there is any doubt as to needing it for further safe flight. Catastrophic failure accompanied by heavy vibration, smoke,
blistering paint, or large trails of oil, on the other hand, indicate a critical situation. The affected engine should be feathered and
the securing failed engine checklist completed. The pilot should divert to the nearest suitable airport and declare an emergency
with ATC for priority handling.
Fuel crossfeed is a method of getting fuel from a tank on one side of the airplane to an operating engine on the other. Crossfeed is
used for extended single-engine operation. If a suitable airport is close at hand, there is no need to consider crossfeed. If prolonged
flight on a single-engine is inevitable due to airport non-availability, then crossfeed allows use of fuel that would otherwise
be unavailable to the operating engine. It also permits the pilot to balance the fuel consumption to avoid an out-o f-balance
wing heaviness.
The AFM/POH procedures for crossfeed vary widely. Thorough fuel system knowledge is essential if crossfeed is to be conducted .
Fuel selector positions and fuel boost pump usage for crossfeed differ greatly among multiengine airplanes. Prior to landing,
crossfeed should be terminated and the operating engine returned to its main tank fuel supply.
If
the airplane is above its single-engine absolute ceiling at the time of engine failure, it slowly loses altitude. The pilot
should maintain V YSE to minimize the rate of altitude loss. This “drift down” rate is greatest immediately following the
failure and decreases as the single-engine ceiling is approached. Due to performance variations caused by engine and propeller wear,
turbulence, and pilot technique, the airplane may not maintain altitude even at its published single-engine ceiling. Any further
rate of sink, however, would likely be modest.
An engine failure in a descent or other low power setting can be deceiving. The dramatic yaw and performance loss is absent. At very
low power settings, the pilot may not even be aware of a failure. If a failure is suspected, the pilot should advance both
engine mixtures, propellers, and throttles significantly, to the takeoff settings if necessary, to correctly identify the failed engine. The
power on the operative engine can always be reduced later.
Engine Inoperative Approach and Landing
The approach and landing with OEI is essentially the same as a two-engine approach and landing. The traffic pattern should be flown
at similar altitudes, airspeeds, and key positions as a two-engine approach. The differences are the reduced power available and the
fact that the remaining thrust is asymmetrical. A higher-than-normal power setting is necessary on the operative engine.
With adequate airspeed and performance, the landing gear can still be extended on the downwind leg. In which case it should
be confirmed DOWN no later than abeam the intended point of landing. Performance permitting, initial extension of wing
flaps (typically 10°) and a descent from pattern altitude can also be initiated on the downwind leg. The airspeed should be no slower
than VYSE. The direction of the traffic pattern, and therefore the turns, is of no consequence as far as airplane controllability
and performance are concerned. It is perfectly acceptable to make turns toward the failed engine.
On the base leg, if performance is adequate, the flaps may be extended to an intermediate setting (typically 25°). If the performance is
inadequate, as measured by decay in airspeed or high sink rate, delay further flap extension until closer to the runway. VYSE is still the
minimum airspeed to maintain.
On final approach, a normal 3° glidepath to a landing is desirable. Visual approach slope indicator (VASI) or other vertical path
lighting aids should be utilized if available. Slightly steeper approaches may be acceptable. However, a long, flat, low approach
should be avoided. Large, sudden power applications or reductions should also be avoided. Maintain V YSE until the landing is
assured, then slow to 1.3 V SO or the AFM/POH recommended speed. The final flap setting may be delayed until the landing is
assured or the airplane may be landed with partial flaps.
The airplane should remain in trim throughout. The pilot should be prepared, however, for a rudder trim change as the power of the
operating engine is reduced to idle in the round out just prior to touchdown. With drag from only one windmilling propeller, the
airplane tends to float more than on a two-engine approach. Precise airspeed control therefore is essential, especially when landing on
a short, wet, and/or slippery surface.
Some pilots favor resetting the rudder trim to neutral on final and compensating for yaw by holding rudder pressure for the remainder
of the approach. This eliminates the rudder trim change close to the ground as the throttle is closed during the round out for landing.
This technique eliminates the need for groping for the rudder trim and manipulating it to neutral during final approach, which many
pilots find to be highly distracting. AFM/POH recommendations or personal preference should be used.
A single-engine go-around on final approach may not be possible. As a practical matter in single-engine approaches, once the airplane
is on final approach with landing gear and flaps extended, it is committed to land on the intended runway, on another runway,
a taxiway, or grassy infield. Most light-twins do not have the performance to climb on one engine with landing gear and flaps
extended. Considerable altitude is lost while maintaining V YSE and retracting landing gear and flaps. Losses of 500 feet or
more are not unusual. If the landing gear has been lowered with an alternate means of extension, retraction may not be possible,
virtually negating any climb capability.
Multiengine Training Considerations
Flight trainin g in a multiengin e airplan e ca n b e saf ely accomplished if bo th th e instructo r an d th e learn er consid er th e following
factors.
⦁ The participants should conduct a preflight briefing of the objectives, maneuvers, expected learner actions,
and completion standards before the flight begins.
⦁ A clear understanding exists as to how simulated emergencies will be introduced, and what action the
learner is expected to take.
The introduction, practice, and testing of emergency procedures has always been a sensitive subject. Surprising a multiengine learner
with an emergency without a thorough briefing beforehand creates a hazardous condition. Simulated engine failures, for example,
can very quickly become actual emergencies or lead to loss of the airplane when approached carelessly. Stall-spin accidents in
training for emergencies rival the number of stall-spin accidents from actual emergencies. The training risk normally gets mitigated by
a briefing. Pulling circuit breakers is not recommended for training purposes and can lead to a subsequent gear up landing.
Many normal, abnormal, and emergency procedures can be introduced and practiced in the airplane as it sits on the ground without
the engines running. In this respect, the airplane is used as a procedures trainer. The value of this training may be substantial. The
engines do not have to be operating for real learning to occur. Upon completion of a training session, care should be taken to restore
items to their proper positions.
Pilots who do not use a checklist effectively will be at a significant disadvantage in multiengine airplanes. Use of the checklist is
essential to safe operation of airplanes, and it is risky to conduct a flight without one. The manufacturer's checklist or an aftermarket
checklist that conforms to the manufacturer's procedures for the specific make, model, and model year may be used. If there is a
procedural discrepancy between the checklist and the AFM/POH, then the AFM/POH always takes precedence.
Certain immediate action items (such as a respons e to an engin e failure in a critical phase of flight) ar e best committed to memory.
After they are accomplished, and as work load permits, the pilot can compare the action taken with a checklist.
Simulated engine failures during the takeoff ground roll may be accomplished with the mixture control. The simulated failure should
be introduced at a speed no greater than 50 percent of V MC. If a learner does not react promptly by retarding both throttles, the
instructor can always pull the other mixture.
The FAA recommends that all in-flight simulated engine failures below 3,000 feet AGL, be introduced with a smooth reduction of the
throttle. Thus, the engine is kept running and is available for instant use, if necessary. Smooth throttle reduction avoids abusing the
engine and possibly causing damage. Simulation of inflight engine failures below V SSE introduces a very high and unnecessary
training risk.
If the engines are equipped with dynamic crankshaft counterweights, it is essential to make throttle reductions for simulated failures
smoothly. Other areas leading to dynamic counterweight damage include high rpm and low manifold pressure combinations, over-
boosting, and propeller feathering. Severe damage or repetitive abuse to counterweights will eventually lead to engine failure.
Dynamic counterweights are found on larger, more complex engines —instructors may check with maintenance personnel or the
engine manufacturer to determine if their airplane engines are so equipped.
When an instructor simulates an engine failure, the learner should respond with the appropriate memory items and retard the
appropriate propeller control toward the FEATHER position. Assuming zero thrust will be set, the instructor promptly moves th e
propeller control forward and sets the appropriate manifold pressure and rpm. It is vital that the learner be kept informed of the
instructor's intentions. At this point the instructor may say words to the effect, "I have the right engine; you have the left. I have set
zero thrust and the right engine is simulated feathered." Any ambiguity as to who is operating what systems or controls increases the
likelihood of an unintended outcome.
Following a simulated engine failure, the instructor cares for the "failed" engine just as the learner cares for the operative engine. If
zero thrust is set to simulate a feathered propeller, the cowl flap is normally closed and the mixture leaned. An occasional clearing of
the engine is also desirable. If possible, avoid high power applications immediately following a prolonged cool-down at a zero-thrust
power setting. A competent flight instructor teaches the multiengine learner about the critical importance of feathering the propeller in
a timely manner should an actual engine failure situation ever be encountered. A windmilling propeller, in many cases, has given the
improperly trained multiengine pilot the mistaken perception that the engine is still developing useful thrust, resulting in a
psychological reluctance to feather, as feathering results in cessation of propeller rotation. The flight instructor should spend ample
time demonstrating the difference in the performance capabilities of the airplane with a simulated feathered propeller (zero thrust) as
opposed to a windmilling propeller.
Actual and safe propeller feathering for training is performed at altitudes and positions where safe landings on established airports
may be readily accomplished if the propeller will not unfeather. Plan unfeathering and restart to be completed no lower than 3,000
feet AGL. At certain elevations and with many popular multiengine training airplanes, this may be above the single-engine service
ceiling, and level flight will not be possible.
Repeated feathering and unfeathering is hard on the engine and airframe, and is done as necessary to ensure adequate training. The
FAA's Airman Certification Standards for a multiengine class rating contains a task for feathering and unfeathering of one propeller
during flight in airplanes in which it is safe to do so.
While much of this chapter has been devoted to the unique flight characteristics of a multiengine airplane with one engine
inoperative, the modern well-maintained reciprocating engine is remarkably reliable. When training in an airplane, initiation of a
simulated engine inoperative emergency at low altitude normally occurs at a minimum of 400 feet AGL to mitigate the risk involved
and only after the learner has successfully mastered engine inoperative procedures at higher altitudes. Initiating a simulated
low altitude engine inoperative emergency in the airplane at extremely low altitude, immediately after liftoff, or below V SSE
creates a situation where there are non-existent safety margins.
For training in maneuvers that would be hazardous in flight, or for initial and recurrent qualification in an advanced multiengine
airplane, consider a simulator training center or manufacturer's training course. Comprehensive training manuals and classroo m
instruction are available along with system training aids, audio/visuals, and flight training devices and simulators. Training under a
wide variety of environmental and aircraft conditions is available through simulation. Emergency procedures that would be either
dangerous or impossible to accomplish in an airplane can be done safely and effectively in a flight training device or simulator. The
flight training device or simulator need not necessarily duplicate the specific make and model of airplane to be useful. Highly
effective instruction can be obtained in training devices for other makes and models as well as generic training devices.
The majority of multiengine training is conducted in four- to-six place airplanes at weights significantly less than maximum. Single-
engine performance, particularly, at low density altitudes, may be deceptively good. To experience the performance expected a t
higher weights, altitudes and temperatures, the instructor may occasionally artificially limit the amount of manifold pressure available
on the operative engine. Airport operations above the single-engine ceiling can also be simulated in this matter. Avoid loading the
airplane with passengers to practice emergencies at maximum takeoff weight since this practice creates an unnecessary trainin g
hazard.
The use of the touch-and-go landing and takeoff in multiengine flight training has always been somewhat controversial. The value of
the learning experience may be offset by the hazards of reconfiguring the airplane for takeoff in extremely limited time as well as the
loss of the follow-through ordinarily experienced in a full stop landing. Touch-and-goes are not recommended during initial aircraft
familiarization in multiengine airplanes.
If touch-and-goes are to be performed at all, the learner and instructor responsibilities should be carefully briefed prior to each flight.
Following touchdown, the learner will ordinarily maintain directional control while keeping the left hand on the yoke and the right
hand on the throttles. The instructor resets the flaps and trim and announces when the airplane has been reconfigured. The
multiengine airplane uses considerably more runway to perform a touch-and-go than a single-engine airplane. A full stop-taxi back
landing is preferable during initial familiarization. Solo touch-and-goes in twins are strongly discouraged.
Chapter Summary
Small multiengine airplanes handle much like single-engine airplanes as long as both engines are functioning normally. A competent
multiengine pilot, however, acquires the additional knowledge, risk mitigation strategies, and practical skills required to fly a
multiengine airplane in case a loss of thrust from one engine actually occurs. In that case, the pilot will be able to take appropriate
action leading to a safe outcome. Much of this chapter discussed loss of directional control. How to obtain the best performance with
an inoperative engine was also described in detail. These two considerations correspond to the red radial line (V MC) and the blue
radial line (V YSE) on the airspeed indicator. The actions a pilot takes when dealing with stalls, V MC, or best performance vary
greatly. Understanding these concepts, knowing how to mitigate the risks, and possessing the skills to handle an engine failure in a
variety of situations, allows a pilot to enjoy the increased performance and safety provided when flying a multiengine airplane.