What happened
On February 17, 2016, while a Boeing 737-80/00 was in the climb phase of flight, the crew observed a low-pressure indication for the left fuel pump of the center tank. Following the occurrence of the warning, the flight crew performed the required procedures as outlined in the "LOW PRESSURE" checklist. After completing the necessary actions, the crew continued the flight to the intended destination airport.
Upon arrival, the operator's Maintenance Control Center (MCC) was notified of the technical malfunction. Under the provisions of the Minimum Equipment List (MEL) 28.2.B, maintenance personnel cleared the aircraft for flight to a technical base for further inspection.
The investigation
The investigation focused on the cause of the low-pressure signal in the fuel system. During the inspection of the center tank fuel pump system at the maintenance base, technical personnel conducted tests to identify the source of the pressure drop. The investigation established that the malfunction was localized to the electrical components of the pump assembly.
Findings
- The low-pressure indication was caused by a blown fuse located inside the fuel pump.
- Following the replacement of the fuse, the restrictions previously applied under the MEL were removed, and the aircraft was returned to service without further limitations.