Will the main engines start without their respective boost pumps running?

Will the main engines start without their respective boost pumps running?

• A. Yes
• B. No, both must be running
• C. Only engine 1 can start
• D. Only engine 2 can start

Answer: (A)

The main idea here is that light-off of the engines does not require the boost pumps to be running. On the CRJ-550, the engine start sequence is designed so ignition can occur even if the electric boost pumps are off. The boost pumps mainly ensure adequate fuel pressure during normal operation and when high fuel flow is needed, but they aren’t a prerequisite for the initial light-off of the engines. In practice, you would still monitor fuel pressure and follow procedures if pump pressure is insufficient, but the system is designed to allow starting without the boost pumps.

The main idea here is that light-off of the engines does not require the boost pumps to be running. On the CRJ-550, the engine start sequence is designed so ignition can occur even if the electric boost pumps are off. The boost pumps mainly ensure adequate fuel pressure during normal operation and when high fuel flow is needed, but they aren’t a prerequisite for the initial light-off of the engines. In practice, you would still monitor fuel pressure and follow procedures if pump pressure is insufficient, but the system is designed to allow starting without the boost pumps.