FAA Powerplant Written Practice Test

How does the clutch in pneumatic starters operate?

1. Manually engaged and disengaged

2. Automatically engaged and automatically disengaged

3. Requires operator intervention

4. Differentiates between engine types

The correct answer is: Automatically engaged and automatically disengaged

The clutch in pneumatic starters operates automatically to engage and disengage. In a pneumatic starter system, the engagement of the clutch occurs when the starter is activated and air pressure is applied. This pressure facilitates the connection between the starter motor and the engine's drivetrain, allowing for a smooth operation without the need for manual intervention. Once the engine starts and reaches a certain RPM, the air pressure decreases, leading to the automatic disengagement of the clutch. This design enhances efficiency and reduces the need for the operator to actively manage the starting process, making the system more reliable and straightforward to use. Overall, the automatic nature of the clutch operation is a crucial aspect of pneumatic starters, ensuring a seamless transition between starting the engine and then releasing it for normal operation.