Narrative:

We were scheduled to land with about 7.0 lbs. Of fuel. We noticed the fob (fuel on board) was decreasing below 7.0. The winds were higher than forecast so we didn't think much of it. We did decide to climb ahead of schedule since the winds were no worse higher in an attempt to get back on our burn schedule. Upon reaching [the midpoint of the flight] fob had decreased significantly more; around 4.5 if I remember correctly. This is when we first became concerned that we may need to do a fuel stop if the winds did not subside and the burn trend reverse. We texted dispatch with our fob and concern. I noticed an 800lb fuel imbalance so I did a cross feed while waiting to hear back from dispatch. Dispatch said he was showing us crossing the fixes +/- 200 lbs. After a couple more exchanges with dispatch the fob had dropped to 3.5. We did a FMC position report; dispatch was showing the same thing +/- 200 lbs. The fuel had become imbalanced again so we started looking at alternative explanations than un-forecasted winds. As the fob dropped to 3.0 we decided we were going to have to fuel stop at a minimum. Meanwhile dispatch had sent us a flight plan to [an alternate] if we wanted to; but his info was still showing we were on plan. We had 16.5 fob at this time so we did not feel pressure to act rashly. We looked at options and tried to explain the discrepancy. We did the fuel leak check list and it appeared that we had enough symptoms to confirm that we had a probable leak. We had plenty of fuel so we decided it was not prudent to create another emergency by shutting down #2 engine. We discussed when we would continue check list and shut it down. We determined 2000 lbs in # 2 tank as our bottom line for shut down. At the same time as discussions and checklist were ongoing we started the divert.we did a normal landing [at the alternate] with both engines running. We had fire department check for visible signs of leak. The said #2 was leaking. We shut it down on the taxiway and confirmed the leak had stopped prior to proceeding to gate.

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Original NASA ASRS Text

Title: Boeing 737 flight crew reported a fuel burn in excess of that expected for the flight. Troubleshooting suggested a fuel leak and a successful diversion to a suitable airport was accomplished.

Narrative: We were scheduled to land with about 7.0 lbs. of fuel. We noticed the FOB (Fuel on Board) was decreasing below 7.0. The winds were higher than forecast so we didn't think much of it. We did decide to climb ahead of schedule since the winds were no worse higher in an attempt to get back on our burn schedule. Upon reaching [the midpoint of the flight] FOB had decreased significantly more; around 4.5 if I remember correctly. This is when we first became concerned that we may need to do a fuel stop if the winds did not subside and the burn trend reverse. We texted dispatch with our FOB and concern. I noticed an 800lb fuel imbalance so I did a cross feed while waiting to hear back from dispatch. Dispatch said he was showing us crossing the fixes +/- 200 lbs. After a couple more exchanges with dispatch the FOB had dropped to 3.5. We did a FMC position report; dispatch was showing the same thing +/- 200 lbs. The fuel had become imbalanced again so we started looking at alternative explanations than un-forecasted winds. As the FOB dropped to 3.0 we decided we were going to have to fuel stop at a minimum. Meanwhile Dispatch had sent us a flight plan to [an alternate] if we wanted to; but his info was still showing we were on plan. We had 16.5 FOB at this time so we did not feel pressure to act rashly. We looked at options and tried to explain the discrepancy. We did the fuel leak check list and it appeared that we had enough symptoms to confirm that we had a probable leak. We had plenty of fuel so we decided it was not prudent to create another emergency by shutting down #2 engine. We discussed when we would continue check list and shut it down. We determined 2000 lbs in # 2 tank as our bottom line for shut down. At the same time as discussions and checklist were ongoing we started the divert.We did a normal landing [at the alternate] with both engines running. We had Fire department check for visible signs of leak. The said #2 was leaking. We shut it down on the taxiway and confirmed the leak had stopped prior to proceeding to gate.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.