What is the starter duty cycle for an APU on an LCAC?

The correct choice reflects the operational guidelines for starting an Auxiliary Power Unit (APU) on a Landing Craft Air Cushion (LCAC). An APU is essential for providing initial power and helping to start the main engines. The duty cycle specifically involves a 30-second operational period followed by a mandatory cooling period.

The three repetitions of this cycle are designed to ensure that the APU does not overheat and that its components are kept within safe operational limits. After completing these three starts, the requirement for a mandatory 30-minute cool down allows the APU sufficient time to dissipate heat effectively and maintain its reliability and integrity during subsequent operations.

This structured approach to the starter duty cycle is critical for the longevity and performance of both the APU and the LCAC, emphasizing the importance of cooling intervals in ensuring proper function and preventing thermal overload.