Try FAA A&P Powerplant Free

1.During which stroke of the four-stroke cycle does the spark plug normally fire?

• Near the top of the compression stroke, before top dead center.
• At the beginning of the intake stroke.
• At the very end of the power stroke.

2.How does a gas turbine engine's combustion process differ fundamentally from a reciprocating engine's?

• Combustion is continuous, occurring simultaneously with intake, compression, and expansion at different points in the engine.
• Combustion occurs in discrete strokes just like a reciprocating engine, but at a much higher RPM.
• Gas turbine engines do not use combustion at all to produce thrust.

3.During a differential compression test, where is regulated shop air introduced into the cylinder?

• Through the spark plug hole, with the piston at top dead center on the compression stroke.
• Through the oil filler cap.
• Through the exhaust pipe only.

4.Why is a manifold pressure gauge an essential instrument on an engine with a constant-speed propeller?

• Because RPM alone no longer reflects power output as directly, so manifold pressure serves as a primary power-setting reference alongside RPM.
• Because constant-speed propeller engines have no tachometer installed.
• Manifold pressure gauges are only used on engines without any propeller governor.

5.What distinguishes overheat detection from fire detection in an engine fire protection system?

• Overheat detection warns of an abnormal temperature rise before an actual fire condition exists; fire detection confirms an actual fire.
• Overheat and fire detection are identical functions with no meaningful difference.
• Overheat detection only operates on the ground, while fire detection only operates in flight.

6.What is the purpose of an engine accessory gearbox (accessory case)?

• It provides a shared, engine-driven gear train with mounting pads for multiple accessories such as the generator, magnetos, and fuel pump.
• It exists solely to house the engine's ignition switch.
• It provides electrical power storage independent of the battery.

7.What is the key difference between a wet sump and a dry sump lubrication system?

• A wet sump uses the engine's own crankcase as the oil reservoir, while a dry sump stores oil in a separate external tank.
• A dry sump system requires no oil pump at all.
• A wet sump system is only used on turbine engines, never reciprocating engines.

8.Why can a magneto-equipped reciprocating engine continue running even with a completely dead battery?

• A magneto generates its own ignition voltage internally and requires no external electrical power.
• The battery only powers the fuel system, not the ignition system, on any aircraft engine.
• Magnetos draw power from the propeller's rotation rather than from the engine itself.

9.What creates the pressure drop that draws fuel into the airstream in a float-type carburetor?

• The venturi — a narrowed section of the induction airflow path.
• The mixture control cable acting directly on the fuel bowl.
• The engine's oil pump, which is mechanically linked to the carburetor.

10.What is the primary purpose of the fuel pressure regulator in an engine fuel system?

• To maintain fuel delivery pressure within the range the metering system is designed to work with.
• To convert fuel pressure directly into engine oil pressure.
• To regulate ignition timing based on fuel pressure.