Which device serves both to start an engine and to generate electrical power on some aircraft engines?

Which device serves both to start an engine and to generate electrical power on some aircraft engines?

• A. Starter generator
• B. Starter motor
• C. Alternator
• D. Generator

Answer: (A)

A starter generator provides both starting the engine and generating electrical power. It cranks the engine like a starter motor, then, once the engine reaches sufficient speed, switches to generation mode to supply electrical power and recharge the battery. This switch is typically done with a clutch that disengages the motor from the crankshaft after start, allowing the generator to take over. A starter motor alone only starts, while an alternator or generator alone only provides power and cannot start the engine.

A starter generator provides both starting the engine and generating electrical power. It cranks the engine like a starter motor, then, once the engine reaches sufficient speed, switches to generation mode to supply electrical power and recharge the battery. This switch is typically done with a clutch that disengages the motor from the crankshaft after start, allowing the generator to take over. A starter motor alone only starts, while an alternator or generator alone only provides power and cannot start the engine.