B737 Flight Crew reported a suspected Fuel Leak after takeoff. The Flight Crew ran the QRH and checklists and then requested vectors to return to the departure airport. The suspected Fuel Leak continued to worsen; so the Flight Crew requested priority handling and performed an in flight shut down. When complying with the inflight shutdown QRH; it was discovered that the Cross Feed Valve was still open. The flight crew continued to perform an air turn back and precautionary landing at departure airport.
Synopsis
B737 Flight Crew reported a suspected Fuel Leak after takeoff. The Flight Crew ran the QRH and checklists and then requested vectors to return to the departure airport. The suspected Fuel Leak continued to worsen; so the Flight Crew requested priority handling and performed an in flight shut down. When complying with the inflight shutdown QRH; it was discovered that the Cross Feed Valve was still open. The flight crew continued to perform an air turn back and precautionary landing at departure airport.
Narrative
Shortly after completing the after takeoff checklist I noticed that fuel was flowing from the left fuel tank at a very alarming rate. We thought that there was a fuel leak because of the rapid fuel flow out of the left tank. The First Officer (FO) continued to fly the aircraft while I ran the Engine Fuel Leak QRH. We briefly discussed continuing straight to ZZZ1 but the weather was better in ZZZ and the rate of fuel loss out of the left side was very concerning to us. While I ran the QRH the FO [requested priority handling] and requested vectors back to ZZZ. The rapid loss led us to confirm a fuel leak in the QRH which led us to shutting down the number one engine. We continued to an uneventful single engine landing in ZZZ. After securing the engine we became aware the cross feed valve was open. I know I pointed at it in the QRH and verified it closed. I did not see a dim blue light and did not expect it to be open; because the only time it is open is when I open it. While we did discuss the issue at hand before delving into the QRC we felt a great urgency to act quickly due to the very rapid loss of fuel. A longer safety pause would have been more appropriate. The FO did a great job flying the plane and handling the radios but the approach environment is very distracting.I left the checklist to get ATC SOB count after we [requested priority handling]; and again to talk to the Flight Attendants (FAs) when they felt the plane turning around. Better managing distractions during critical junctures of the checklist would have gone a long way. I feel like I have good working knowledge of the 737 fuel systems; and know that one pump can overpower the others and the high power setting and fuel flow was the reason why the draw on the left side was so alarming. In retrospect there were a number of opportunities to trap this error before becoming an undesirable aircraft state. Fatigue may have been a contributing factor as this incident occurred on daylight savings day. I had a hard time falling asleep and woke up at XA:30 AM body time. My watch estimated my sleep for the night as 4 hours 13 minutes. I was tired that day and using caffeine to get me home. I have learned a lot from previous company guidance on this issue and never wanted to be the one to go down this rabbit hole. Look out for tunnel vision; confirmation bias; don't rush!
Second reporter narrative
Shortly after completing the after takeoff checklist the Captain noticed that fuel was depleting from the left fuel tank at an alarming rate. After a quick discussion we agreed that a fuel leak was suspected. I continued flying the aircraft and took over radio duties while the Captain ran the QRH for fuel leak. I [requested priority handling] and requested radar vectors back to ZZZ after a quick discussion with the Captain as the weather was significantly better there than ZZZ1. The checklist lead us to shut down the left engine and we prepared for a single-engine approach and landing. While on downwind our jump seater noticed that our cross feed valve was in the open position and neither the Captain nor I had caught it. We were so busy and inundated with task-saturation that a step was missed in the QRH. I think we were pretty shocked to see how fast our fuel was depleting from the left side and that caused us to rush the checklist and miss key steps. The volume of radio calls and vectors kept me from doing a great job of backing up the Captain while they ran the checklist. Fatigue was definitely a contributing factor as we had an early van in ZZZ2 on the morning of daylight savings. This is a prime example of needing to slow down and take a better assessment of the situation before rushing to conclusions.
More incidents for this aircraft family →
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.