How long must you wait between APU cranking attempts?

The correct answer is 2 minutes. This waiting period is crucial during APU (Auxiliary Power Unit) cranking attempts because it allows the APU to cool down and ensures that the electrical systems and components have enough time to reset. By waiting for this duration between attempts, you minimize the risk of overheating and physical stress on the APU, which can lead to potential failure or damage. Furthermore, adhering to this protocol helps maintain the integrity of the unit and contributes to more reliable operation in subsequent attempts. Understanding and following these specific timing procedures is vital for safe and effective aircraft operations.