What happened
On July 8, 2015, while performing the before-start procedure at Alicante Airport (LEAL) in Spain, the crew of a Boeing 737-700 identified a malfunction in the fuel system. Specifically, the central fuel pump failed to activate, triggering a "Low Pressure" warning light on the left side of the cockpit.
Following established protocols, the crew performed the necessary checklists to evaluate the situation. The procedures permitted the crew to proceed with engine start, taxi, and the flight to the intended destination. During the flight, the fuel from the center tank was entirely depleted using the secondary pump within that tank.
The investigation
The investigation focused on the technical failure of the fuel delivery system. Upon arrival at the destination, the captain notified the Maintenance Control Center (MCC) and recorded the malfunction in the aircraft technical log. Subsequent ground testing revealed that the issue originated from a faulty fuel pump control module (UFI). After the module was replaced, functional tests confirmed the system was operating correctly, and the aircraft was returned to service without restrictions.