Is ice on the APU inlet screen acceptable?

Ice on the APU inlet screen is not acceptable because it poses significant risks to the function and safety of the Auxiliary Power Unit (APU). The APU requires a steady supply of air for proper operation, and ice accumulation can obstruct this airflow. This obstruction can lead to reduced efficiency, potential overheating, or complete failure of the APU, compromising the power available for aircraft systems and impacting overall flight safety.

Additionally, in icy conditions, the risk of ice shedding can further damage other components if the APU is started while ice is present on the inlet. Therefore, maintaining a clear and unobstructed inlet is essential for the optimal performance and safety of the APU, making the presence of ice an unacceptable condition.