Aircraft General Knowledge: Airframe, Systems, Instruments and Powerplants
Airframe and flight controls
Know the primary structure - fuselage, wing, empennage, landing gear - and how loads travel through the spar and ribs. Questions test the difference between primary controls (aileron, elevator, rudder) and secondary or auxiliary controls (flaps, trim, spoilers). A common trap is assuming trim changes the aircraft's attitude directly; trim relieves control pressure, and the attitude change follows.
Systems
Understand the electrical system (battery, alternator, bus), the pitot-static system, and the vacuum or electrically driven gyros. Learn what happens when the pitot tube ices: the airspeed indicator behaves like an altimeter, reading high in a climb and low in a descent, while the altimeter and vertical speed indicator remain correct. That asymmetry is a favourite exam item.
Instruments
Group instruments by their source: pitot-static (airspeed, altimeter, VSI) and gyroscopic (attitude indicator, heading indicator, turn coordinator). Know each gyro's rigidity and precession behaviour, and the errors - parallax, position error, lag. For the magnetic compass, memorise the turning and acceleration errors: in the Northern Hemisphere, turning through north the compass under-reads, and acceleration produces an apparent turn to the north.
Powerplants
For piston engines, know the four strokes, the purpose of the mixture control, carburettor icing conditions, and the meaning of magneto checks during run-up. A frequent trap: carburettor ice can form at outside temperatures well above freezing, typically in humid air between roughly -5 °C and +25 °C, and is most likely at low power settings such as descent.
Worked example
If the altimeter subscale is set to the wrong pressure, the error is roughly 30 ft per hPa. Setting 1013 instead of 1003 gives about 300 ft of error - enough to fail a minima question. Always convert before choosing an answer.