Question

What is the altitude for APU starting (with normal A/C power supply) and operation? A) 10,000 feet B) 20,000 feet C) 30,000 feet D) 40,000 feet

Answer 1

Typically, an APU (Auxiliary Power Unit) can effectively start and operate up to a height of around 10,000 feet; after this, the decreasing atmospheric pressure can make it difficult for the APU to operate effectively.

Step-by-step explanation:

The altitude for APU starting and operation, with normal A/C power supply is typically up to a height of 10,000 feet (approximately 3000 meters). This altitude is practical because the air above this height becomes increasingly thin, making it difficult for the APU (Auxiliary Power Unit) to work effectively. Given the conditions provided for two altitudes, 1500 m (about 5000 feet) and 3000 m (about 10,000 feet) where the atmospheric pressures are 8.59 x 10^4 N/m² and 7.00 x 10^4 N/m², respectively; it is seen that the performance of the APU can be maintained at an efficient level.

Learn more about APU Operational Altitude