Date: 201505
Local time of day: 0601-1200
Location: IAH.Airport, TX
Aircraft: B767 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Takeoff / Launch
ATC / advisory: Tower IAH
Aircraft component: Flap/Slat Control System
Component problem: Improperly Operated
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Distraction; Fatigue
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Overcame Equipment Problem
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: [We were] fatigued (last flight of 4 after being up all night) and unclear on the initial taxi instructions upon leaving gate area prompting discussion between pilots and request for clarification from ATC as to which taxiway we were to hold short of. There was also concern regarding construction impeding the normal taxi route to anticipated and briefed departure runway. This was our original interruption which I believe hampered communication and execution of takeoff flap setting and Before Takeoff Checklist. Last minute runway change...requiring associated reprogramming of runway specific SID in FMC and re-referencing TLR for performance was another. This departure runway change was offered (not solicited by us) with the stipulation that we 'be ready for an IMMEDIATE takeoff' and subsequent takeoff clearance was given with 'no delay; traffic on short final'. In retrospect; this was a classic setup; causing just enough distraction and interruptions during taxi out for checklist and flow disruption. Upon advancing thrust levers to Takeoff; warning sounded due to flaps not in the takeoff configuration. I retarded the thrust levers while the First Officer (FO) immediately recognized the cause and selected the flaps to 15 position. We contacted tower and cleared the runway expeditiously to allow for landing traffic. Accomplished appropriate checklist and returned to runway for takeoff.This has never happened to me before (and will never happen again). For me; one who considers checklist discipline and diligence to be utmost in priority during all phases of flight; this event provides clear evidence for the need to accomplish Taxi and/or Before Take Off checklists prior to movement of aircraft. I believe this has been documented by human factor studies; implemented at other airlines and; to my understanding; endorsed and encouraged by the FAA. I for one; as a personal technique and safeguard; will never release the parking brake for taxi until I have clearance from the marshaller AND have flaps selected for takeoff AND verified takeoff warning items (trim & speed brake) properly set. Perhaps it would be an improvement to our procedures and an enhancement to safety to call for and accomplish the Before Takeoff checklist; or at least the 'big' items; prior to commencing taxi where changes can cause interruption and distraction.




Synopsis: A B767 flight crew failed to complete the Before Takeoff checklist due to distractions and discovered that the flaps were not set for takeoff when the Takeoff Warning horn sounded.