What should be done if the APU oil pressure is low during operation?

If the APU oil pressure is low during operation, shutting down the APU is the appropriate action. Low oil pressure indicates that the lubrication system is not functioning properly, which can lead to increased friction and overheating of internal components. This could cause significant damage to the engine and possibly result in a complete failure of the APU.

The shutdown procedure is crucial to prevent further deterioration of the APU and to ensure safety. Continuing operation under low oil pressure can exacerbate existing issues and lead to more severe and costly repairs. Ignoring the pressure gauge or attempting to adjust the throttle will not resolve the underlying issue of inadequate oil pressure and could further jeopardize the operational integrity of the APU.