Narrative:

We were scheduled for a turn with a 1 hour 18 min layover. After about 30 mins on the ground, we were told our airplane was going to be taken and that our inbound airplane would arrive 10 mins after we were scheduled to depart. Also, the inbound airplane may not be mechanically sound and we would just have to wait and see if we were going to cancel or go. When the airplane arrived, I could not find any discrepancy and neither could the mechanic even though it had been written up on at least 3 previous flts. We had to wait for maintenance control to make a decision to release the airplane. If I agreed to take the airplane, they would release it. I consented with the proviso that I would return if the failure recurred prior to takeoff. Next the ramp closed due to lightning associated with high winds and very heavy rain. Later, almost simultaneously, the ramp opened and the agent came down and said you can leave immediately. We were now over 2 hours late. Checklists were completed and pushback began. I remember being especially attentive to the fire detection system throughout the start sequence. I wasn't sure if the first officer was aware that the agent's fuel load disagreed with our release and I told him to contact operations. I remember the tug operator calling for me to set the brakes and I acknowledged. The after start checklist was completed. I remember scanning the sky looking for a routing clear of the storms off to the north and east. I remember being aware of the first officer's conversation with operations and of the simultaneous pushback of a B757 on our left wing. I thought it was odd that both of us were pushed back to edge of the ramp. Our position now put us in line with gate X. The first officer thought an appropriate amount of time had passed and saw a tug in position at gate X (we pushed from gate Z), and called for taxi rather than challenge me for an acknowledgement of the 'thumbs up.' his call followed seconds after the B757 to our left was given taxi instructions. With his trigger to me, 'taxi behind the company,' I released the brakes, heard the noise of the tires hitting the tow bar and instantly knew what had occurred. It seemed like an eternity before the ground crew plugged in and answered my question if everyone was ok. The trip was scheduled for 3 days with 9 legs. The first day had only 2 working legs which were followed by a 3 hour layover followed by a 1 hour 49 min deadhead to the overnight. The day was exhausting for me. The sitting around on the ground and in the air for me is not restful. Although there was time to eat and go to bed early, I did not sleep well and did not awake refreshed. It could have been psychological as, on the day of the error, we faced a 13 hour 30 min duty day with yet another 3+ hour situation time. The error occurred very close to the circadian time of maximum sleepiness and after 8 hours on duty. None of these factors, when viewed in isolation, were that overwhelming. In fact, I can provide personal circumstances far more complex that did not result in a safety breech. These very same circumstances on any other day may not have resulted in a safety breech, but in fact a potentially tragic event did occur on aug/tue/03 with me in command. When I heard of others taxiing without a ground clearance, and even when an first officer would clear me to taxi, and I reminded him we were not disconnected, I knew this would never happen to me. It is too easy of a catch. Never. How can this be prevented in the future by other crews who do not have visual contact with their tug? What tools can be provided to better manage this error? Procedure and monitoring are barriers (human interaction and communications) that may be adversely affected by the very same external distrs to both crew members. Fatigue can also affect both crew members. When an error can result in a fatality, an automatic or physical/mechanical barrier is preferable to a barrier that can be penetrated by human error. Physical mechanical solutions: 1) provide a large orange cone on the ramp at the airport's 10 O'clock position while the tug is not visible. 2) position nosewheel chocks untiltug is visible. The cone solution may be difficult to implement, but I feel its physical presence offers the best solution. Chocked wheels may not be effective in icy conditions. Checklist solutions: 1) add a separate taxi checklist for aircraft with 'invisible' tugs. 2) the last item on the after start checklist should be -- verify thumps up/wave off/salute (you choose the verbiage) received. A single trigger flow followed by an after start checklist is the next strongest barrier to error for the pushback event. This is impractical due to the inconsistent relationship between engine start and pushback completion. A less effective solution would be to add a 'thumbs up' verification to the after start checklist with the recognition that the flow may be interrupted and the checklist may not be a strict 'do-verify' as it is today. The flow would end at the autobrakes, rejected takeoff, and the checklist would be completed only after the thumbs up. (The 'shoulder harness verify on' would be eliminated as only 'critical' items would remain on the new checklist.) the other alternative is to add a separate taxi checklist with its own trigger. This may not be met well on the line, but if this isn't an isolated occurrence, a new checklist section would certainly elevate emphasis on ground crew release and clearance.

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Original NASA ASRS Text

Title: B767 CREW GOT IN A RUSH BECAUSE THE LATE ARRIVING ACFT HAD MAINT PROBS, TSTMS WERE IN THE AREA, AND THE FUEL LOAD WAS NOT CORRECT. THIS DELAYED THE DEP CONSIDERABLY. THE CAPT RELEASED THE ACFT BRAKES BEFORE CLRED BY THE GND CREW, AND HIT THE TOW BAR.

Narrative: WE WERE SCHEDULED FOR A TURN WITH A 1 HR 18 MIN LAYOVER. AFTER ABOUT 30 MINS ON THE GND, WE WERE TOLD OUR AIRPLANE WAS GOING TO BE TAKEN AND THAT OUR INBOUND AIRPLANE WOULD ARRIVE 10 MINS AFTER WE WERE SCHEDULED TO DEPART. ALSO, THE INBOUND AIRPLANE MAY NOT BE MECHANICALLY SOUND AND WE WOULD JUST HAVE TO WAIT AND SEE IF WE WERE GOING TO CANCEL OR GO. WHEN THE AIRPLANE ARRIVED, I COULD NOT FIND ANY DISCREPANCY AND NEITHER COULD THE MECH EVEN THOUGH IT HAD BEEN WRITTEN UP ON AT LEAST 3 PREVIOUS FLTS. WE HAD TO WAIT FOR MAINT CTL TO MAKE A DECISION TO RELEASE THE AIRPLANE. IF I AGREED TO TAKE THE AIRPLANE, THEY WOULD RELEASE IT. I CONSENTED WITH THE PROVISO THAT I WOULD RETURN IF THE FAILURE RECURRED PRIOR TO TKOF. NEXT THE RAMP CLOSED DUE TO LIGHTNING ASSOCIATED WITH HIGH WINDS AND VERY HVY RAIN. LATER, ALMOST SIMULTANEOUSLY, THE RAMP OPENED AND THE AGENT CAME DOWN AND SAID YOU CAN LEAVE IMMEDIATELY. WE WERE NOW OVER 2 HRS LATE. CHKLISTS WERE COMPLETED AND PUSHBACK BEGAN. I REMEMBER BEING ESPECIALLY ATTENTIVE TO THE FIRE DETECTION SYS THROUGHOUT THE START SEQUENCE. I WASN'T SURE IF THE FO WAS AWARE THAT THE AGENT'S FUEL LOAD DISAGREED WITH OUR RELEASE AND I TOLD HIM TO CONTACT OPS. I REMEMBER THE TUG OPERATOR CALLING FOR ME TO SET THE BRAKES AND I ACKNOWLEDGED. THE AFTER START CHKLIST WAS COMPLETED. I REMEMBER SCANNING THE SKY LOOKING FOR A ROUTING CLR OF THE STORMS OFF TO THE N AND E. I REMEMBER BEING AWARE OF THE FO'S CONVERSATION WITH OPS AND OF THE SIMULTANEOUS PUSHBACK OF A B757 ON OUR L WING. I THOUGHT IT WAS ODD THAT BOTH OF US WERE PUSHED BACK TO EDGE OF THE RAMP. OUR POS NOW PUT US IN LINE WITH GATE X. THE FO THOUGHT AN APPROPRIATE AMOUNT OF TIME HAD PASSED AND SAW A TUG IN POS AT GATE X (WE PUSHED FROM GATE Z), AND CALLED FOR TAXI RATHER THAN CHALLENGE ME FOR AN ACKNOWLEDGEMENT OF THE 'THUMBS UP.' HIS CALL FOLLOWED SECONDS AFTER THE B757 TO OUR L WAS GIVEN TAXI INSTRUCTIONS. WITH HIS TRIGGER TO ME, 'TAXI BEHIND THE COMPANY,' I RELEASED THE BRAKES, HEARD THE NOISE OF THE TIRES HITTING THE TOW BAR AND INSTANTLY KNEW WHAT HAD OCCURRED. IT SEEMED LIKE AN ETERNITY BEFORE THE GND CREW PLUGGED IN AND ANSWERED MY QUESTION IF EVERYONE WAS OK. THE TRIP WAS SCHEDULED FOR 3 DAYS WITH 9 LEGS. THE FIRST DAY HAD ONLY 2 WORKING LEGS WHICH WERE FOLLOWED BY A 3 HR LAYOVER FOLLOWED BY A 1 HR 49 MIN DEADHEAD TO THE OVERNIGHT. THE DAY WAS EXHAUSTING FOR ME. THE SITTING AROUND ON THE GND AND IN THE AIR FOR ME IS NOT RESTFUL. ALTHOUGH THERE WAS TIME TO EAT AND GO TO BED EARLY, I DID NOT SLEEP WELL AND DID NOT AWAKE REFRESHED. IT COULD HAVE BEEN PSYCHOLOGICAL AS, ON THE DAY OF THE ERROR, WE FACED A 13 HR 30 MIN DUTY DAY WITH YET ANOTHER 3+ HR SIT TIME. THE ERROR OCCURRED VERY CLOSE TO THE CIRCADIAN TIME OF MAX SLEEPINESS AND AFTER 8 HRS ON DUTY. NONE OF THESE FACTORS, WHEN VIEWED IN ISOLATION, WERE THAT OVERWHELMING. IN FACT, I CAN PROVIDE PERSONAL CIRCUMSTANCES FAR MORE COMPLEX THAT DID NOT RESULT IN A SAFETY BREECH. THESE VERY SAME CIRCUMSTANCES ON ANY OTHER DAY MAY NOT HAVE RESULTED IN A SAFETY BREECH, BUT IN FACT A POTENTIALLY TRAGIC EVENT DID OCCUR ON AUG/TUE/03 WITH ME IN COMMAND. WHEN I HEARD OF OTHERS TAXIING WITHOUT A GND CLRNC, AND EVEN WHEN AN FO WOULD CLR ME TO TAXI, AND I REMINDED HIM WE WERE NOT DISCONNECTED, I KNEW THIS WOULD NEVER HAPPEN TO ME. IT IS TOO EASY OF A CATCH. NEVER. HOW CAN THIS BE PREVENTED IN THE FUTURE BY OTHER CREWS WHO DO NOT HAVE VISUAL CONTACT WITH THEIR TUG? WHAT TOOLS CAN BE PROVIDED TO BETTER MANAGE THIS ERROR? PROC AND MONITORING ARE BARRIERS (HUMAN INTERACTION AND COMS) THAT MAY BE ADVERSELY AFFECTED BY THE VERY SAME EXTERNAL DISTRS TO BOTH CREW MEMBERS. FATIGUE CAN ALSO AFFECT BOTH CREW MEMBERS. WHEN AN ERROR CAN RESULT IN A FATALITY, AN AUTOMATIC OR PHYSICAL/MECHANICAL BARRIER IS PREFERABLE TO A BARRIER THAT CAN BE PENETRATED BY HUMAN ERROR. PHYSICAL MECHANICAL SOLUTIONS: 1) PROVIDE A LARGE ORANGE CONE ON THE RAMP AT THE ARPT'S 10 O'CLOCK POS WHILE THE TUG IS NOT VISIBLE. 2) POS NOSEWHEEL CHOCKS UNTILTUG IS VISIBLE. THE CONE SOLUTION MAY BE DIFFICULT TO IMPLEMENT, BUT I FEEL ITS PHYSICAL PRESENCE OFFERS THE BEST SOLUTION. CHOCKED WHEELS MAY NOT BE EFFECTIVE IN ICY CONDITIONS. CHKLIST SOLUTIONS: 1) ADD A SEPARATE TAXI CHKLIST FOR ACFT WITH 'INVISIBLE' TUGS. 2) THE LAST ITEM ON THE AFTER START CHKLIST SHOULD BE -- VERIFY THUMPS UP/WAVE OFF/SALUTE (YOU CHOOSE THE VERBIAGE) RECEIVED. A SINGLE TRIGGER FLOW FOLLOWED BY AN AFTER START CHKLIST IS THE NEXT STRONGEST BARRIER TO ERROR FOR THE PUSHBACK EVENT. THIS IS IMPRACTICAL DUE TO THE INCONSISTENT RELATIONSHIP BTWN ENG START AND PUSHBACK COMPLETION. A LESS EFFECTIVE SOLUTION WOULD BE TO ADD A 'THUMBS UP' VERIFICATION TO THE AFTER START CHKLIST WITH THE RECOGNITION THAT THE FLOW MAY BE INTERRUPTED AND THE CHKLIST MAY NOT BE A STRICT 'DO-VERIFY' AS IT IS TODAY. THE FLOW WOULD END AT THE AUTOBRAKES, REJECTED TKOF, AND THE CHKLIST WOULD BE COMPLETED ONLY AFTER THE THUMBS UP. (THE 'SHOULDER HARNESS VERIFY ON' WOULD BE ELIMINATED AS ONLY 'CRITICAL' ITEMS WOULD REMAIN ON THE NEW CHKLIST.) THE OTHER ALTERNATIVE IS TO ADD A SEPARATE TAXI CHKLIST WITH ITS OWN TRIGGER. THIS MAY NOT BE MET WELL ON THE LINE, BUT IF THIS ISN'T AN ISOLATED OCCURRENCE, A NEW CHKLIST SECTION WOULD CERTAINLY ELEVATE EMPHASIS ON GND CREW RELEASE AND CLRNC.

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.