For engine start or motoring in flight during 2nd through 5th attempts, what is the recommended on/off pattern?

For engine start or motoring in flight during 2nd through 5th attempts, what is the recommended on/off pattern?

• A. 60 Seconds ON, 5 Minutes OFF
• B. 120 Seconds ON, 10 Seconds OFF
• C. 90 Seconds ON, 5 Minutes OFF
• D. 30 Seconds ON, 5 Minutes OFF

Answer: (A)

The key idea is protecting the starter and engine while you attempt multiple starts. For the 2nd through 5th engine start or motoring attempts, you run the starter for 60 seconds, then allow a 5-minute cooldown. That 60-second on period is long enough to attempt a safe rotation and verify the engine is responding, while the lengthy 5-minute off period gives the starter motor and associated components time to cool and the engine to shed heat. Using longer on times or shorter off times risks overheating and possible damage, while too short an on time may not allow the engine to reach a stable rotation. This pattern provides a reliable balance for multiple start attempts.

The key idea is protecting the starter and engine while you attempt multiple starts. For the 2nd through 5th engine start or motoring attempts, you run the starter for 60 seconds, then allow a 5-minute cooldown. That 60-second on period is long enough to attempt a safe rotation and verify the engine is responding, while the lengthy 5-minute off period gives the starter motor and associated components time to cool and the engine to shed heat. Using longer on times or shorter off times risks overheating and possible damage, while too short an on time may not allow the engine to reach a stable rotation. This pattern provides a reliable balance for multiple start attempts.