Narrative:

I relayed the clearance to our ground and tug crew that we were cleared to push after the traffic had cleared behind us. It took a while to move and I may have reset the brake. (I always set the brakes during taxi when we stop, but never during pushback.) ground copied and complied with the clearance. I was really surprised that the brakes were not released. I could not recall if I did release or if I reset them after they were released. I read the recent reports about brake release related incidents and towbars, and wondered how, and why we were making these mistakes. Luckily no one was injured, and the damage was limited to the shear pins on the towbar. I think what contributed to this error are a combination of factors. Our obsession with on time departure, our relief pilot advised me that it was schedule departure, and asked if I wanted to give the on time out, as our first officer was giving me the pushback clearance. (He later mentioned that it may have distraction my normal flow.) ground crew starts to push, after a delay waiting for the traffic to clear, without stating, 'we are starting the push', (even though I may have confirmed that parking brakes were released) prior to push. Should amend procedure so that ground crew required to verbally restate 'starting the push' any time there is any delay during the operation. The ground crew was superb, highly professional, they got us out with a minimum delay, and within mins we completed the pushback. We got back to destination on schedule.

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Original NASA ASRS Text

Title: A B767-300 GND CREW CLRED FOR PUSHBACK AFTER TFC CLRED. CAPT INADVERTENTLY RESET PARKING BRAKE WHILE WAITING TO COMPLETE PUSHBACK CAISOMG TOWBAR SHEAR PINS TO SHEAR.

Narrative: I RELAYED THE CLRNC TO OUR GND AND TUG CREW THAT WE WERE CLRED TO PUSH AFTER THE TFC HAD CLRED BEHIND US. IT TOOK A WHILE TO MOVE AND I MAY HAVE RESET THE BRAKE. (I ALWAYS SET THE BRAKES DURING TAXI WHEN WE STOP, BUT NEVER DURING PUSHBACK.) GND COPIED AND COMPLIED WITH THE CLRNC. I WAS REALLY SURPRISED THAT THE BRAKES WERE NOT RELEASED. I COULD NOT RECALL IF I DID RELEASE OR IF I RESET THEM AFTER THEY WERE RELEASED. I READ THE RECENT RPTS ABOUT BRAKE RELEASE RELATED INCIDENTS AND TOWBARS, AND WONDERED HOW, AND WHY WE WERE MAKING THESE MISTAKES. LUCKILY NO ONE WAS INJURED, AND THE DAMAGE WAS LIMITED TO THE SHEAR PINS ON THE TOWBAR. I THINK WHAT CONTRIBUTED TO THIS ERROR ARE A COMBINATION OF FACTORS. OUR OBSESSION WITH ON TIME DEP, OUR RELIEF PLT ADVISED ME THAT IT WAS SCHEDULE DEP, AND ASKED IF I WANTED TO GIVE THE ON TIME OUT, AS OUR FO WAS GIVING ME THE PUSHBACK CLRNC. (HE LATER MENTIONED THAT IT MAY HAVE DISTR MY NORMAL FLOW.) GND CREW STARTS TO PUSH, AFTER A DELAY WAITING FOR THE TFC TO CLR, WITHOUT STATING, 'WE ARE STARTING THE PUSH', (EVEN THOUGH I MAY HAVE CONFIRMED THAT PARKING BRAKES WERE RELEASED) PRIOR TO PUSH. SHOULD AMEND PROC SO THAT GND CREW REQUIRED TO VERBALLY RESTATE 'STARTING THE PUSH' ANY TIME THERE IS ANY DELAY DURING THE OP. THE GND CREW WAS SUPERB, HIGHLY PROFESSIONAL, THEY GOT US OUT WITH A MINIMUM DELAY, AND WITHIN MINS WE COMPLETED THE PUSHBACK. WE GOT BACK TO DEST ON SCHEDULE.

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.