Question

(APU limits) An overspeed condition exists when the tachometer reads _____ RPM.

Option 1: 110%
Option 2: 120%
Option 3: 130%
Option 4: 140%

Answer 1

An overspeed condition occurs when the tachometer reads 110% of the maximum operational RPM for an APU, marking the threshold for potential damage or failure.

Step-by-step explanation:

An overspeed condition in an Auxiliary Power Unit (APU) can be a critical situation for aircraft operations. The question concerns at what tachometer reading an overspeed condition would be indicated. Considering typical overspeed limits for APUs, the likely correct answer from the given options would be Option 1: 110% of the maximum operational RPM. Exceeding this threshold would constitute an overspeed condition, requiring immediate attention and potential shutdown of the APU to prevent damages or failure.