Ex. 2 - Ancillary Controls/Operation of Aircraft Systems


To teach the requirements for, and the proper use, of carburettor heat, alternate air, mixture controls, cowl flaps, heating, defrosting, ventilation and any other ancillary controls applicable to the aeroplane type.


Many ancillary controls may be new to the student; therefore, detailed training is required.  Proper use of certain controls is necessary for safe and optimum use of the aeroplane.  Misuse could lead to an actual in-flight emergency.

Essential Background Knowledge

Review and explain for the aeroplane being used:

  • carburetted engines:
    - carburettor icing
    - intake icing
    - causes, symptoms, effects on performance
  • fuel injected engines
    - intake icing
    - alternate air usage
    - causes symptoms and effects on performance
    - turbocharger precautions and fault symptoms
  • mixture control:
    - during takeoff, climb, cruise, descents
    - use of fuel flow and exhaust gas temperature gauges
  • cooling considerations:
    - use of cowl flaps
    - before and during one engine inoperative operation
  • cabin heating and ventilation, including heater and windscreen defogging equipment.
  • primary flight controls
  • aileron, rudder and elevator trim
  • landing gear and retraction system
  • flap system
  • brakes
  • electrical, including alternator or generator
  • hydraulics
  • fuel systems
    - carburetted engines
    - fuel injected engines
    - cross-feed
    - engine priming system
  • turbocharger
  • propeller and constant speed governor
  • de-icing/anti-icing
  • pressurization
  • crew and passenger oxygen
  • any other systems applicable to type

Advice to Instructors

Prior to flying, spend sufficient time in the cockpit with the student to become familiar with the location and operation of the various ancillary controls.

Students learn best by doing. Let them operate the ancillary controls as much as possible.  Lack of student proficiency may be the result of an instructor's tendency to operate these controls rather than allowing the student to do so.  Traditionally, the practical operation of the cabin heater is poorly taught, as the heater controls are often located on the lower right-hand panel, in easy reach by the instructor.  As a result, the candidate neglects heater operation as an integral part of pilot duties during flight tests, even in winter.

This may be the first time the student has encountered some of these items.  Before flight, ensure that the student understands when, why and how they are used.

Instruction and Student Practice

During pre-flight briefings, question the student on the operation of the applicable' ancillary controls during various phases of the intended flight. Use the aeroplane checklist as a guide.

When satisfied that the student understands when, why, and how to operate the applicable controls, use close supervision to ensure that the tasks are completed correctly.

Ask questions to ensure that the student is not performing a function by "rote" or simply because it appears on the checklist.