Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)
Aircraft General Knowledge
This domain covers the airframe, systems, powerplant and electrics at the level needed to manage a light twin or single-engine aircraft safely and to answer systems questions, not to design components.
Powerplant and propeller. A four-stroke piston engine produces power on the power stroke; the mixture control sets fuel/air ratio, and best power is slightly rich of peak EGT. Detonation is uncontrolled explosive combustion, while pre-ignition is ignition before the spark; both cause high CHT and can destroy an engine. Carburettor ice forms at 0–20 °C with high humidity and shows as a slow RPM drop; apply carburettor heat fully and expect a further drop before recovery. A constant-speed propeller maintains selected RPM by changing blade angle.
Electrics and systems. The battery supplies power for starting and is the standby source; the alternator carries the load in flight. An ammeter or loadmeter shows whether the alternator is charging. If the alternator fails, the battery will supply the essential bus for a limited time. Circuit breakers protect wiring; never reset a tripped breaker more than once without finding the cause.
Worked example
During cruise, RPM falls slowly and the engine runs rough; carburettor heat is applied and RPM drops further, then rises. Reasoning: the initial drop was ice; the further drop is melted ice entering the engine; recovery confirms carburettor ice.
Traps
Carburettor heat bypasses the filter, so avoid it in dusty conditions. Do not assume a failed alternator means immediate engine failure - the magnetos are independent. Know which systems are electrically dependent.