What MSP indicates the need for servicing APU?

The correct choice indicates that the Maintenance Signal Procedure (MSP) code 984 is specifically designated to signal the need for servicing the Auxiliary Power Unit (APU). The APU is a crucial component of the F/A-18 E/F aircraft, providing power to onboard systems when the main engines are not running, and it also plays a role in starting the engines. Regular servicing is essential to ensure its reliable operation and functionality.

The MSP codes are part of the aircraft's maintenance and servicing protocols, where each code corresponds to specific actions required for the aircraft's components. In this case, the usage of code 984 indicates a maintenance need that directly relates to the APU's operational efficiency and readiness.

Understanding these codes is vital for plane captains and maintenance personnel to ensure that all aspects of the aircraft remain in optimal working condition, as neglecting such servicing could lead to failures that impact flight operations and safety. Each of the other codes corresponds to different maintenance requirements that do not pertain to the APU specifically.