Ground start of engine groups 1 and 2 has what crank limit?

Ground start of engine groups 1 and 2 has what crank limit?

• A. 90 sec ON / 10 sec OFF
• B. 120 sec ON / 10 sec OFF
• C. 90 sec ON / 5 min OFF
• D. 120 sec ON / 5 min OFF

Answer: (A)

Cranking limits during a ground start are in place to protect the starter and related systems from overheating. For engines in groups 1 and 2, you may crank for up to 90 seconds continuously, then you must allow a 10-second off period before attempting to crank again. This 90/10 cycle prevents thermal damage to the starter and keeps the start sequence within safe limits. The other durations would either push the starter beyond safe thermal limits or impose unnecessarily long cooldowns, which is not allowed by the procedures.

Cranking limits during a ground start are in place to protect the starter and related systems from overheating. For engines in groups 1 and 2, you may crank for up to 90 seconds continuously, then you must allow a 10-second off period before attempting to crank again. This 90/10 cycle prevents thermal damage to the starter and keeps the start sequence within safe limits. The other durations would either push the starter beyond safe thermal limits or impose unnecessarily long cooldowns, which is not allowed by the procedures.