When low pressure is detected in a left engine fuel feed line, which boost pump activates?

In the CRJ550, when low pressure is detected in a left engine fuel feed line, both the left and right boost pumps are activated as a precautionary measure to maintain fuel flow and ensure engine reliability. This dual activation serves to compensate for potential issues in the fuel system and to provide adequate fueling to the left engine in case of a malfunction. By activating both pumps, the system enhances the redundancy and ensures consistent fuel pressure is maintained, thereby preventing engine flameout due to inadequate fuel supply. The operation of both pumps in response to low pressure conditions is a key safety feature designed to mitigate risks associated with fuel delivery to the engines.

In this context, the choice stating that only the left boost pump would activate would not account for the redundancy built into the system, and stating that no boost pumps activate overlooks the necessity for fuel pressure maintenance during such events. Thus, the activation of both boost pumps under low pressure conditions reflects the aircraft's design for flexibility and safety in fuel management.