Narrative:

During irregular ground engine start and push back the nose gear steering was pressurized during aircraft push back. Nose gear taxi light mounting bracket shear bolts were damaged by tow bar. The local station start procedure was requested prior to engine start. This procedure incorporates starting the #1 engine at the gate utilizing an external air source and then pushing back the aircraft. Cockpit crew was interrupted 2 or 3 times during the prestart checklist via communications with ground and cabin crew. Prior to start of #1 engine, captain instructed first officer to closely monitor the duct pressure during start due to use of external air and previously intermittent start switch. After #1 engine start and during 'before push back/taxi checklist' crew was distraction by aft service door light and subsequent conversation with cabin crew. Captain was further distraction by inability to hear the ground crew on the intercom above the noise of #1 engine (microphone away from ground crewman face). Push back proceeded normally until ground crew turned the aircraft at which time captain heard and felt a 'tow bar slap' (not uncommon and indicative of rough handling/worn tow bar). Captain instinctively reached for the 'a' pumps to confirm their position and found the 'a' pump in the on position and turned it off. At this time captain noticed that the left 'B' pump was off (should have been on). Upon completion of push back and disconnect, the ground crew returned to the aircraft and informed captain that the taxi light was loose and the aircraft was pulled back into a gate for maintenance. The 'a' hydraulic system was pressurized during push back and a worn (but evidently svcable) tow bar was used to push the aircraft. This situation occurred because the crew allowed external cockpit distrs and ground crew haste to interfere with their duties. Prevention of similar incidences can be averted by crews not allowing themselves to be distraction by external forces, especially when operating with irregular procedures.

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Original NASA ASRS Text

Title: FAULTY RAMP OP PUSH BACK PROCS CREATES MINOR ACFT DAMAGE.

Narrative: DURING IRREGULAR GND ENG START AND PUSH BACK THE NOSE GEAR STEERING WAS PRESSURIZED DURING ACFT PUSH BACK. NOSE GEAR TAXI LIGHT MOUNTING BRACKET SHEAR BOLTS WERE DAMAGED BY TOW BAR. THE LCL STATION START PROC WAS REQUESTED PRIOR TO ENG START. THIS PROC INCORPORATES STARTING THE #1 ENG AT THE GATE UTILIZING AN EXTERNAL AIR SOURCE AND THEN PUSHING BACK THE ACFT. COCKPIT CREW WAS INTERRUPTED 2 OR 3 TIMES DURING THE PRESTART CHKLIST VIA COMS WITH GND AND CABIN CREW. PRIOR TO START OF #1 ENG, CAPT INSTRUCTED FO TO CLOSELY MONITOR THE DUCT PRESSURE DURING START DUE TO USE OF EXTERNAL AIR AND PREVIOUSLY INTERMITTENT START SWITCH. AFTER #1 ENG START AND DURING 'BEFORE PUSH BACK/TAXI CHKLIST' CREW WAS DISTR BY AFT SVC DOOR LIGHT AND SUBSEQUENT CONVERSATION WITH CABIN CREW. CAPT WAS FURTHER DISTR BY INABILITY TO HEAR THE GND CREW ON THE INTERCOM ABOVE THE NOISE OF #1 ENG (MIC AWAY FROM GND CREWMAN FACE). PUSH BACK PROCEEDED NORMALLY UNTIL GND CREW TURNED THE ACFT AT WHICH TIME CAPT HEARD AND FELT A 'TOW BAR SLAP' (NOT UNCOMMON AND INDICATIVE OF ROUGH HANDLING/WORN TOW BAR). CAPT INSTINCTIVELY REACHED FOR THE 'A' PUMPS TO CONFIRM THEIR POS AND FOUND THE 'A' PUMP IN THE ON POS AND TURNED IT OFF. AT THIS TIME CAPT NOTICED THAT THE L 'B' PUMP WAS OFF (SHOULD HAVE BEEN ON). UPON COMPLETION OF PUSH BACK AND DISCONNECT, THE GND CREW RETURNED TO THE ACFT AND INFORMED CAPT THAT THE TAXI LIGHT WAS LOOSE AND THE ACFT WAS PULLED BACK INTO A GATE FOR MAINT. THE 'A' HYD SYS WAS PRESSURIZED DURING PUSH BACK AND A WORN (BUT EVIDENTLY SVCABLE) TOW BAR WAS USED TO PUSH THE ACFT. THIS SITUATION OCCURRED BECAUSE THE CREW ALLOWED EXTERNAL COCKPIT DISTRS AND GND CREW HASTE TO INTERFERE WITH THEIR DUTIES. PREVENTION OF SIMILAR INCIDENCES CAN BE AVERTED BY CREWS NOT ALLOWING THEMSELVES TO BE DISTR BY EXTERNAL FORCES, ESPECIALLY WHEN OPERATING WITH IRREGULAR PROCS.

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.