Ex. 6 - Engine Failure (Cruise Flight) and Manoeuvring with One Engine Inoperative


To teach the student:

  • to identify the failed engine
  • the procedure to be followed when an engine failure occurs in cruise flight
  • to complete all necessary checks in accordance with the “Engine Failure in Flight” checklist and the Pilot Operating Handbook (POH)
  • to manoeuvre the aeroplane safely and effectively with one engine inoperative


In the proper configuration, using approved procedures, multi-engine aeroplanes are controllable after the failure of an engine.  Incorrect configurations may require more power than is available from the operating engine.  Incorrect procedures may lead to loss of aeroplane control.

Essential Background Knowledge

Explain related theory:

  • definition of critical engine
  • factors affecting VMC
  • one engine inoperative stall/spin characteristics

Explain aeroplane handling:

  • POH/AFM procedure
  • control of yaw
  • roll and pitch
  • bank towards live engine
  • operating speeds
  • critical engine
  • zero-thrust power settings

Explain operational considerations:

  • service ceiling
  • drift-down altitude
  • fuel management
  • range calculations
  • affected systems
  • hot/cold temperatures

Outline safety considerations:

  • lookout
  • altitude
  • proximity to the airport
  • density altitude

Engine Failure (Cruise Flight)

In the absence of a procedure in the POH/AFM, these steps should be taken. Note that BOLDFACE denotes memory items. With the majority of emergencies, certain procedures must be performed immediately from memory. Students should be made aware of such items during simulation on an engine failure.
CONTROL yaw, roll, airspeed
POWER mixture, propellers, throttles
DRAG confirm landing gear up, flaps up
IDENTIFY failed engine
VERIFY failed engine by reducing throttle of suspected failed engine
CAUSE CHECK if time and altitude permit, attempt to assess and correct problem using appropriate checklist.  Then advance throttle to determine if engine is developing power.
FEATHER propeller on the failed engine
SECURE complete the “Engine Failure in Flight” checklist and monitor the operating engine and its related systems

Proceed to the nearest suitable airport, taking into consideration the facilities, surface wind, elevation, obstacles and the seriousness of the emergency.


Advice to Instructors

Prior to flight it must made be clear that should an actual emergency occur, the instructor will state "I have control" and assume control of the aeroplane. Actions for the student to follow will be delegated as required.

Density altitude must be considered when working in areas with high terrain during conditions of warmer than standard temperatures.

Simulated engine failures should be conducted within 15 miles of an airport, in the event that mismanagement or errors occur during student practice.  Remember, “The hand is faster than the eye.”  Altitude for this exercise must be in accordance with the POH/AFM or at least 3,000 feet above ground level.  Prolonged manoeuvring with an engine at idle or zero-thrust should be avoided, especially in colder weather.

Encourage the student to do the engine failure checks only a few items at a time (once the memory items are completed) and to monitor the aeroplane between these times.  This will help to overcome the natural tendency to give most attention to checks and neglect lookout and control of the aeroplane.

Pilots should be aware that relying on engine gauge indications could be misleading in trying to identify the inoperative engine.  Point out that manifold pressures can remain normal during some engine failures and give the pilot the false impression that everything is all right.  On the other hand, gauges can be very useful in determining partial power losses or power surges when the "dead foot, dead engine" rule is not giving a true indication.  All evidence of an engine failure must be considered when the condition is not obvious.

Should the suspected cause of an engine failure be fuel contamination, the pilot must avoid the use of cross-feed.

Have the student simulate feathering the propeller by moving the propeller control lever a short distance towards the "feather" position.  The instructor must block the lever to prevent an actual feathering of the propeller with a “live” engine.  Avoid substituting a verbal drill for this action.  The "hands-on" drill will promote the proficiency needed to select the correct lever during an actual engine failure emergency.  Then, simulate a feathered condition by adjusting manifold pressure and rpm to achieve zero thrust.

Engine gauges should also be monitored for indications of impending problems at all times, such as decreasing oil pressure or increasing temperatures.  In such cases, the pilot may elect to shut down the affected engine, having the advantage of doing so in a deliberate and planned manner.  Engine temperatures and pressures must be monitored to avoid excessive cooling or overheating while operating on one engine.

Caution students on turning toward the inoperative engine at airspeeds below VSSE or VXSE and if using higher angles of bank.  There may not be enough control input to level the wings for straight and level flight unless power is reduced.

Discuss situations in which an in-flight emergency engine failure/shutdown would call for an unplanned landing at a nearby airport, rather than continuing to the destination airport, which might otherwise be more suitable.  An example of such a situation would be an engine fire in flight.

Instruction and Student Practice

Demonstrate the cockpit drills and the use of the emergency checklist on the ground in the aeroplane, followed by student practice.  Caution must be exercised to avoid inadvertent selection of items such as landing gear "UP", while on the ground.

Once airborne, allow the student to establish cruise flight and complete the required checklist items.

Actual engine shutdowns for training purposes are not recommended, as the training value is not worth the added safety risk and abuse of engines and airframe.  Simulated engine failures should be conducted within 15 miles of a suitable landing site in case an inadvertent actual engine shutdown occurs, after which the engine cannot be restarted.  Schools operating out of airports at higher elevations must also be cautious during warmer temperatures.  Single-engine service ceiling and performance can be drastically affected under these conditions.

Simulate the engine failure by reducing the throttle to idle, while calling out "simulated".  Complete the engine failure drill in accordance with the POH or the procedures outlined on the previous page.

When these checks have been completed, and you are ready to simulate feathering the propeller, adjust the manifold pressure and rpm to simulate by setting zero thrust.  Consult the POH for zero thrust power settings prior to flight.  Complete the engine securing items by referring to the appropriate emergency checklist.

Ensure that all procedures are carried out completely and correctly.  Concentrate on the accuracy of the checks rather than the speed at which they are performed.

Emphasize that control of the aeroplane is the prime concern.  Ensure that the aeroplane is banked 3-5 degrees towards the operating engine.  Also, lookout must not be allowed to suffer, even though you and the student will be busy inside the aeroplane.

Briefly demonstrate the aeroplane's ability to manoeuvre in level flight, climbs, descents and turns of up to 30 degrees of bank.

Using the in-flight engine restart and propeller unfeathering checklists, simulate a re-start of the “inoperative” engine and resume normal cruise flight.  Return control of the aeroplane to the student, allowing the student to practise the procedure in its entirety.  When simulating the engine failure, obscure the selected control from the students view. 

VMC Demonstration

You do not have to conduct a VMC demonstration during training for this rating, yet many instructors do.  This can be valuable, but extreme caution must be exercised during the demonstration. Some POHs recommend a procedure for the demonstration.  In the absence of a published procedure, instructors may demonstrate this using the following guidelines:
  • Passengers are not to be carried
  • Ensure that you have adequate altitude for recovery from an unusual attitude, should one develop.
  • Both engines must be developing power, one at idle, the other at maximum power.
  • Allow the aeroplane to decelerate slowly while maintaining directional control.
  • For an extra safety measure, use only half-rudder input. This will allow the symptoms of VMC to be experienced at a speed higher than the actual VMC.
  • Recover as soon as directional control cannot be maintained.
  • Reduce the power on the operating engine, or reduce the pitch attitude, or both.
  • Failure to recover at the first indication of VMC can lead to a spin.


The published VMC is determined at a standard sea-level density altitude and will decrease with a gain in altitude, unless you have turbocharged piston engines.  At a given indicated airspeed, the flight controls will have the same effectiveness, regardless of altitude.  Since the operative engine is producing less power at the higher “safe” altitude, there is less asymmetric thrust, torque and yawing force for the rudder to overcome.

A less experienced instructor, who in the interest of safety climbs to a higher altitude for a VMC demonstration, may find that he/she has entered a situation where VMC has decreased to below the stall speed and ends up demonstrating a full-power single-engine stall and spin.