When selecting the bleed source during bleed duct operations, which choice should be made?

When selecting the bleed source during bleed duct operations, which choice should be made?

• A. BLEED SOURCE - SELECT non-affected engine source
• B. BLEED VALVES - MANUAL
• C. ISOL - CLOSED
• D. ECS synoptic page - SELECT to determine affected side

Answer: (A)

When you have to manage bleed air from two engines, you want the bleed source to come from the engine that is not affected by the issue. Selecting the non-affected engine as the bleed source keeps clean, uncontaminated air flowing to the pneumatic systems and maintains proper pressure, since the affected engine’s bleed could be leaking or blocked. This avoids pulling air through a compromised path and preserves system performance for the cabin and avionics needs. Using manual bleed valve control or leaving isolations closed would not achieve the needed source selection, and using the ECS diagnostic page is about identifying the affected side rather than choosing which engine supplies the bleed.

When you have to manage bleed air from two engines, you want the bleed source to come from the engine that is not affected by the issue. Selecting the non-affected engine as the bleed source keeps clean, uncontaminated air flowing to the pneumatic systems and maintains proper pressure, since the affected engine’s bleed could be leaking or blocked. This avoids pulling air through a compromised path and preserves system performance for the cabin and avionics needs. Using manual bleed valve control or leaving isolations closed would not achieve the needed source selection, and using the ECS diagnostic page is about identifying the affected side rather than choosing which engine supplies the bleed.