Definition
An electric motor mounted on the engine that engages the engine's flywheel or crankshaft gear to rotate the engine fast enough for it to start. It draws power from the aircraft battery (or external power) and is activated by the ignition key or starter switch.
Plain English
A small electric motor that spins the engine over until it catches and runs on its own.
Context Anchor
Encountered during engine starting, especially when using the start switch or key before the engine is running.
Why Pilots Care
A reliable starter motor allows safe, consistent engine starts; failure on the ramp can delay departure or force alternative procedures such as hand-propping.
Intuition Check
The starter motor does not keep the engine running. It only turns the engine during the start; after that, the engine runs by burning fuel and air.
Example Sentence 1
The pilot turned the ignition key to START, and the starter motor engaged the engine until it fired and ran on its own.
Example Sentence 2
After the engine started, the starter motor automatically disengaged to avoid damage from high RPM.