B737 Undifferentiated or Other Model
Situational Awareness; Workload; Troubleshooting
Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural FAR; Inflight Event / Encounter Weather / Turbulence; Inflight Event / Encounter Fuel Issue
Flight Crew Diverted; Flight Crew Took Evasive Action
Human Factors; Procedure; Weather
After extended ground delay and snow/deicing ops at our departure airport; aircraft departed for transcontinental flight with dispatched Minimum Takeoff Fuel +600 lbs. Early on during cruise; it became evident that arrival fuel would be 5000 lbs (release planned for 6200 lbs). Captain and FO established this as their absolute minimum and worked with dispatch to maximize burn efficiency. Meanwhile; enroute fuel stop contingencies were discussed and pilots decided upon an airport about an hour short of the filed destination as a fuel divert if need be. Approximately half way through the flight it was determined that arrival fuel would be 4500 lbs and dispatch relayed that there were flow control measures being taken into the destination. At this point crew decided upon and coordinated fuel stop as well as coordinated subsequent flight plan with dispatch. Crew determined that basic FAR 117 duty day would be insufficient to continue to the filed destination; however; given that fuel stop was unplanned; a review of FAR 117 by way of the FOM and union guidance showed it would be possible within the 2 hour extension and crew/dispatch concurrence. FO informed Captain that he was good with extending provided it was possible within legal limits and then performed preflight duties to ready aircraft for second leg while Captain conversed with Dispatch. It was determined and understood by all the mentioned parties that FAR 117 limits (with extension) would allow the crew to legally dispatch to the final destination provided no significant delays occurred during the fueling stop. Aircraft was turned and departed within 45 minutes of arrival and the flight to final destination took 1.1 hours. [Scheduling] shows 1:25 on this leg and a 1010 TFT (Total Flight Time) with 1317 Duty. This was within my understanding of FAR 117 limits with the 2 hour extension hence I was unaware of an error until informed.
A B737 on a transcontinental flight diverted for fuel due to unplanned fuel usage and extended their duty day two hours to comply with FAR 117 limitations.