Narrative:

Ramp personnel called and said we were all clear and ready for pushback. We received clearance and started to push. When cleared for engine start the left engine was started. The tug then started to turn when a large lurch occurred with a loud bang. The tug stopped very quickly and we were told the bypass pin had failed and that the nosewheel was now jammed into the tug. Maintenance had to come get the tug loose and we were pulled to gate for repairs. We started from gate xx. Maintenance later mentioned that a pin was never installed. I am not sure if it was or not as we had turned during pushback, but no engines were running at that time only electric pumps which this super tug may have been able to over power. Either way I am now positively asking ground personnel if the bypass pin is installed.

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Original NASA ASRS Text

Title: A B757-200 INCURRED DAMAGE TO THE NOSE GEAR AND TOWBAR WHEN THE L ENG WAS STARTED DURING PUSHBACK WITHOUT THE NOSE STEERING BYPASS PIN INSTALLED.

Narrative: RAMP PERSONNEL CALLED AND SAID WE WERE ALL CLR AND READY FOR PUSHBACK. WE RECEIVED CLRNC AND STARTED TO PUSH. WHEN CLRED FOR ENG START THE L ENG WAS STARTED. THE TUG THEN STARTED TO TURN WHEN A LARGE LURCH OCCURRED WITH A LOUD BANG. THE TUG STOPPED VERY QUICKLY AND WE WERE TOLD THE BYPASS PIN HAD FAILED AND THAT THE NOSEWHEEL WAS NOW JAMMED INTO THE TUG. MAINT HAD TO COME GET THE TUG LOOSE AND WE WERE PULLED TO GATE FOR REPAIRS. WE STARTED FROM GATE XX. MAINT LATER MENTIONED THAT A PIN WAS NEVER INSTALLED. I AM NOT SURE IF IT WAS OR NOT AS WE HAD TURNED DURING PUSHBACK, BUT NO ENGS WERE RUNNING AT THAT TIME ONLY ELECTRIC PUMPS WHICH THIS SUPER TUG MAY HAVE BEEN ABLE TO OVER PWR. EITHER WAY I AM NOW POSITIVELY ASKING GND PERSONNEL IF THE BYPASS PIN IS INSTALLED.

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.