What is the APU maximum rotor speed?

The maximum rotor speed for an Auxiliary Power Unit (APU) is specified to be 108% of its rated speed. This figure is critical because it defines the operational limits for the APU, ensuring safe and efficient performance. Operating above this threshold can lead to mechanical failure or damage, which can compromise both the APU and the systems it supports.

This maximum rotatory speed is determined during the design and testing phases of the APU and is based on the APU's capacity to safely handle loads and mechanical stresses during operation. Understanding this limit is essential for maintenance personnel and pilots to avoid exceeding parameters, which could jeopardize safety and operational integrity.

While other options present higher percentages, they surpass the acceptable maximum rotor speed, marking them as unsuitable for safe operation. Thus, the identification of 108% as the APU maximum rotor speed aligns with manufacturer specifications and operational guidelines.