Aircraft General Knowledge - Airframe, Systems, Electrics, Powerplant and Emergency Equipment
This domain covers airframe construction, flight controls, hydraulic, electrical and pneumatic systems, powerplant operation and emergency equipment. The exam favours system purpose, failure indications and correct immediate actions rather than deep design mathematics.
Airframe and controls
- Semi-monocoque stressed-skin structures carry loads through skin, stringers, frames, spars and ribs.
- Primary controls are aileron, elevator and rudder; flaps and trim are secondary.
- Differential ailerons reduce adverse yaw; rudder coordinates the turn.
Systems
- Hydraulics power landing gear, brakes, flaps and some flight controls; monitor pressure and quantity.
- Electrics: battery, alternator or generator, bus bar and circuit breakers. The ammeter or loadmeter shows charge or discharge.
- Fuel, pressurisation, ice protection and fire detection are common system questions.
Powerplant
- Reciprocating engines: induction, carburettor icing, magnetos, mixture and constant-speed propeller.
- Turbines: N1/N2, EGT, fuel control, and surge or stall recognition.
Emergency equipment
- ELT transmits on 406 MHz to the COSPAS-SARSAT system and 121.5 MHz for local homing.
- Fire extinguishers, life jackets, oxygen and first-aid kits are checked by location, quantity and serviceability.
Worked example
In cruise the ammeter shows continuous discharge and bus voltage falls. The alternator has probably failed. Reduce non-essential electrical load, keep the battery for essential equipment, advise ATC and plan to land at the nearest suitable aerodrome. Do not reset a circuit breaker repeatedly.
Traps
- Applying carburettor heat raises intake temperature but reduces power; it is not a cure for all rough running.
- Confusing alternator and generator indications.
- Resetting a tripped breaker beyond the approved limit.
- Forgetting that an ELT is not a substitute for a mayday call.