B737 flight crew reported diverting to an alternate airport after identifying a fuel system malfunction in flight.
Synopsis
B737 flight crew reported diverting to an alternate airport after identifying a fuel system malfunction in flight.
Narrative
Flight XXXX ZZZ1 - ZZZ; got howgozit and noticed remaining fuel at destination would be 1000 lbs less than planned. I began monitoring fuel flow. At approximately 4 hrs into the flight the center tank was empty so I turned off the center tank pumps. The wing tank were showing balanced but once the center pumps were turned off the No 1 tank began rapidly decreasing; in the first 2 minutes the No 1 tank lost 300 lbs; then starting steadying until there was a 400 lb difference. At this time we agreed there was a problem and I gave the aircraft controls to the First Officer while I contacted Dispatch to coordinate with Dispatch and Maintenance Control. Dispatch; Maintenance Control; and myself decided it was best to land at the nearest suitable airport. I told Dispatch I was requesting priority handling and ended the conversation. I dictated priority with ZZZ Center and requested vectors to ZZZ2. Then I talked with the flight attendants and made an announcement to the passengers that we would be diverting to ZZZ2. We landed without incident and the fire department did a runway sweep then checked the plane for a fuel leak but did not find or notice anything. At the gate one fuel pump was on for the running APU; Line Maintenance was in the flight deck with us and we all noticed the fuel still rapidly decreasing and losing approximately 700 lbs in about 20 minutes.
Second reporter narrative
Flight XXXX operating from ZZZ to ZZZ1. During climb out we noticed we were showing 1000 lbs less at destination compared to howgozit. We continued to monitor. At approximately 4 hours into flight when center tanks were empty; the Captain turned off the center tank pumps. The wing tanks were showing balanced. Once center pumps were off the number 1 tank began rapidly decreasing. In the first 2 minutes a 300 lb imbalance occurred; The imbalance increased at a slower rate to 400 lbs. we agreed there was a problem. The Captain transferred controls to the First Officer and contacted Dispatch and company. We chose to divert to ZZZ2 and requested priority handling; The landing was normal and uneventful. The fire department inspected the runway and followed the aircraft to the gate. They inspected the wing and engine for a fuel leak and found nothing. At gate when fuel pump was running to power APU with Maintenance in the flight deck the number 1 fuel tank lost an additional 700 lbs in 20 minutes.
More incidents for this aircraft family →
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.