If operating above 8000 ft MSL, both boost pumps shall be on to prevent a feed tank failure. What altitude triggers this requirement?

If operating above 8000 ft MSL, both boost pumps shall be on to prevent a feed tank failure. What altitude triggers this requirement?

• A. 6000 ft MSL
• B. 10000 ft MSL
• C. 8000 ft MSL
• D. 12000 ft MSL

Answer: (C)

Fuel pressure to the engine must be maintained reliably as you operate at higher elevations. Boost pumps provide that pressure and flow to the engine’s feed line, and using both pumps gives you redundancy and greater flow capacity. At lower altitudes and power settings, a single pump can keep the engine fed. But as you climb and the system experiences greater suction losses and potential pressure drops, a single pump may not guarantee adequate fuel pressure to the engine, increasing the risk of feed starvation and possible engine failure. The procedure defines a specific altitude at which the you must switch to both pumps. Crossing that altitude ensures there is enough fuel pressure to prevent the feed tank from failing under higher demand and reduced ambient pressure. Below that point, one pump is sufficient; above it, both pumps are required to maintain reliable engine fuel supply.

Fuel pressure to the engine must be maintained reliably as you operate at higher elevations. Boost pumps provide that pressure and flow to the engine’s feed line, and using both pumps gives you redundancy and greater flow capacity. At lower altitudes and power settings, a single pump can keep the engine fed. But as you climb and the system experiences greater suction losses and potential pressure drops, a single pump may not guarantee adequate fuel pressure to the engine, increasing the risk of feed starvation and possible engine failure.

The procedure defines a specific altitude at which the you must switch to both pumps. Crossing that altitude ensures there is enough fuel pressure to prevent the feed tank from failing under higher demand and reduced ambient pressure. Below that point, one pump is sufficient; above it, both pumps are required to maintain reliable engine fuel supply.