Which two APU parameters share the same 33,000 ft altitude value?

Which two APU parameters share the same 33,000 ft altitude value?

• A. APU Continuous Operation Alt and APU Continuous Operation Elec Gen Use
• B. APU Max Start Alt and APU Max Alt Engine Start
• C. APU Max Alt Bleed Use and APU Max Start Alt
• D. APU Max Alt Engine Start and APU Max Alt Bleed Use

Answer: (A)

The main idea here is that certain APU limits are tied to the continuous-operation capability, not to starting or bleed functions. The APU can run continuously and provide electrical power up to a specific altitude, and that same ceiling applies whether you’re using the APU for continuous operation or specifically for electric generation. Since both “Continuous Operation Alt” and “Continuous Operation Elec Gen Use” describe that same continuous-use ceiling, they share the 33,000 ft value. Other limits (like maximum altitude to start the APU, or maximum altitude for engine start and for bleed use) reflect different performance requirements and typically have different ceilings, so they don’t match this continuous-operation value.

The main idea here is that certain APU limits are tied to the continuous-operation capability, not to starting or bleed functions. The APU can run continuously and provide electrical power up to a specific altitude, and that same ceiling applies whether you’re using the APU for continuous operation or specifically for electric generation. Since both “Continuous Operation Alt” and “Continuous Operation Elec Gen Use” describe that same continuous-use ceiling, they share the 33,000 ft value. Other limits (like maximum altitude to start the APU, or maximum altitude for engine start and for bleed use) reflect different performance requirements and typically have different ceilings, so they don’t match this continuous-operation value.