What does the FLEX ROLLING BLEEDS OPEN message indicate regarding the APU status?

What does the FLEX ROLLING BLEEDS OPEN message indicate regarding the APU status?

• A. APU is Off
• B. APU is On
• C. Bleed Valve Open
• D. Bleed Valve Closed

Answer: (A)

Bleed air sources and how they’re used is the key idea here. On many jets, bleed air for the environmental control system and for engine starting can come from either the APU or from the engine bleed sources. The phrase FLEX ROLLING BLEEDS OPEN points to the engine bleed system being used to supply those bleed air paths, rather than the APU. In this context, that means the APU is not providing bleed air, so its bleed path is not active. The open engine bleeds are supplying the required air, which is why the message indicates the APU status as off. If the APU were supplying bleed air, you’d expect the bleed indication to reflect the APU bleed being active instead.

Bleed air sources and how they’re used is the key idea here. On many jets, bleed air for the environmental control system and for engine starting can come from either the APU or from the engine bleed sources. The phrase FLEX ROLLING BLEEDS OPEN points to the engine bleed system being used to supply those bleed air paths, rather than the APU.

In this context, that means the APU is not providing bleed air, so its bleed path is not active. The open engine bleeds are supplying the required air, which is why the message indicates the APU status as off. If the APU were supplying bleed air, you’d expect the bleed indication to reflect the APU bleed being active instead.