Narrative:

Chain of events: our duty period began at XA05 and was scheduled to finish at XK55 for a total of 11 hours 50 mins of scheduled duty time. Due to maintenance delays, a diversion to avoid severe WX and headwinds, we were behind schedule. Our last 2 legs were mei-lft and lft-dfw. The dispatcher gave us a 2-LEG flight release. En route to lft, I calculated we must take off from lft by XN44 based on the en route flight time of 1 hour 21 mins in order for us to arrive at dfw before 16 hours was exceeded. The flight arrived at the dfw gate at XP05 -- exactly at 16 hours of duty time, however, our duty time did not end until XP20. This resulted in a 16 hour 15 min duty period for the day. In review, I see 2 mistakes made. First, I used the en route flight time on the flight release instead of the scheduled flight time (1 hour 21 mins on the release versus 1 hour 50 mins on the schedule). Hence, taxi time was not accounted for. The second error was not including the 15 mins of duty time deleted once a flight is blocked in. The latest we should have departed the gate at lft was XN00. Human performance considerations: a factor that might have contributed to the error is fatigue due to the previously mentioned delays, flying conditions, and 8 hours 50 mins of flying completed prior to the final leg (10 hours 5 mins total once the last leg was complete).

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Original NASA ASRS Text

Title: E120 CREW WAS SCHEDULED BEYOND MAX ALLOWABLE DUTY TIME.

Narrative: CHAIN OF EVENTS: OUR DUTY PERIOD BEGAN AT XA05 AND WAS SCHEDULED TO FINISH AT XK55 FOR A TOTAL OF 11 HRS 50 MINS OF SCHEDULED DUTY TIME. DUE TO MAINT DELAYS, A DIVERSION TO AVOID SEVERE WX AND HEADWINDS, WE WERE BEHIND SCHEDULE. OUR LAST 2 LEGS WERE MEI-LFT AND LFT-DFW. THE DISPATCHER GAVE US A 2-LEG FLT RELEASE. ENRTE TO LFT, I CALCULATED WE MUST TAKE OFF FROM LFT BY XN44 BASED ON THE ENRTE FLT TIME OF 1 HR 21 MINS IN ORDER FOR US TO ARRIVE AT DFW BEFORE 16 HRS WAS EXCEEDED. THE FLT ARRIVED AT THE DFW GATE AT XP05 -- EXACTLY AT 16 HRS OF DUTY TIME, HOWEVER, OUR DUTY TIME DID NOT END UNTIL XP20. THIS RESULTED IN A 16 HR 15 MIN DUTY PERIOD FOR THE DAY. IN REVIEW, I SEE 2 MISTAKES MADE. FIRST, I USED THE ENRTE FLT TIME ON THE FLT RELEASE INSTEAD OF THE SCHEDULED FLT TIME (1 HR 21 MINS ON THE RELEASE VERSUS 1 HR 50 MINS ON THE SCHEDULE). HENCE, TAXI TIME WAS NOT ACCOUNTED FOR. THE SECOND ERROR WAS NOT INCLUDING THE 15 MINS OF DUTY TIME DELETED ONCE A FLT IS BLOCKED IN. THE LATEST WE SHOULD HAVE DEPARTED THE GATE AT LFT WAS XN00. HUMAN PERFORMANCE CONSIDERATIONS: A FACTOR THAT MIGHT HAVE CONTRIBUTED TO THE ERROR IS FATIGUE DUE TO THE PREVIOUSLY MENTIONED DELAYS, FLYING CONDITIONS, AND 8 HRS 50 MINS OF FLYING COMPLETED PRIOR TO THE FINAL LEG (10 HRS 5 MINS TOTAL ONCE THE LAST LEG WAS COMPLETE).

Data retrieved from NASA's ASRS site as of July 2007 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.