B737 Next Generation Undifferentiated
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 267
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Other / Unknown
Flight Crew Became Reoriented; Flight Crew Rejected Takeoff; Flight Crew Took Evasive Action
Procedure; Aircraft; Human Factors
We were cleared for takeoff Runway 06. First Officer was flying. We had just gotten takeoff power set and a Master Caution (doors aft entry) light illuminated. We rejected takeoff at 57 knots. We notified Tower and advised the Passengers. We turned off at F2; cleared the runway; and the door light extinguished. I called the Flight Attendants (FA) and the C-FA informed me that she saw the door handle not in the horizontal detent; and put it in the closed position as we exited runway.  We advised Control Tower we needed to stop aircraft. We called Dispatch Desk; and he put me on hold to confer with personnel. He got back to me to insure it was low speed reject and I said yes 57 knots.  Dispatcher said we were good to depart. I then had him amend our min takeoff fuel to 18.5.
At approximately 55 knots during the takeoff roll; a caution light illuminated. The caution light was indicated by 'doors' on the recall panel and 'aft entry' (left side) on the overhead panel. I was the Pilot Flying and the Captain rejected the takeoff. After rejecting and within approximately 10 seconds the light extinguished. After exiting the runway; the Captain had a brief conversation with one of the FAs via the intercom. The FA reported that she noticed (after we rejected) that the aft entry door handle was not fully in the locked position. She pushed the handle down which caused the light to extinguish. The Captain called Dispatch and Dispatch conferred with Maintenance. Everybody agreed that it was safe to continue and a write-up was not necessary. Dispatch amended the Release with a new Minimum Takeoff [fuel] of 18.5. We then had an uneventful takeoff.
B737NG flight crew reported rejecting takeoff due to a master caution and door warning.