What is the delay in minutes between APU cranking attempts?

• A. 2 minutes
• B. 5 minutes
• C. 1 minute
• D. 3 minutes

Answer: (A)

When starting an APU, you need a cooldown period between cranking attempts to protect the starter motor and the electrical system. The starter draws a lot of current and generates a lot of heat, so waiting allows heat to dissipate and the system to reset, reducing the risk of overheating or component wear on a quick restart. Two minutes gives enough time for cooling without adding unnecessary delay. Shorter waits may not let things cool enough, while longer waits aren’t needed for normal procedures. So the delay between cranking attempts is two minutes.