Aircraft General Knowledge and Systems
Airframe, powerplant, systems
You must understand the reciprocating engine cycle, the role of the carburettor vs fuel injection, mixture control, magneto ignition, and the constant-speed propeller (governor, oil pressure, pitch vs RPM). Know the electrical system (alternator, battery, bus), hydraulics (where fitted), pitot-static and gyroscopic instruments, and pressurisation on turboprops/jets.
Systems that generate questions
- Fuel system: tanks, selector, primer, boost pump, and vapour lock susceptibility.
- Carburettor icing: most likely at 0–20 °C with high humidity; carb heat raises intake temperature but reduces power.
- Electrical failure: alternator out → battery-only, load shedding, radio/nav degradation.
- Landing gear and brakes: retraction, squat switch, anti-skid.
- Ice protection: pitot heat, propeller de-ice, boots.
Traps
- Confusing carburettor ice (throttle/venturi) with airframe ice (structural).
- Mixing RPM vs manifold pressure in constant-speed propeller logic.
- Forgetting that pitot heat protects the pitot tube, not the static port.
- Assuming a failed alternator means immediate engine failure - it does not in a battery-ignition engine.
Worked example / rule of thumb
Carb icing risk band: −10 to +20 °C with visible moisture or high humidity. Rule of thumb: if you suspect carb ice, apply carb heat fully, expect a temporary RPM drop as ice melts, then a rise.
For engine roughness on one magneto: expect a small RPM drop; excessive drop indicates ignition or plug problems.