Narrative:

I was on this flight, seated in the cockpit jump seat, and was not monitoring radio or interphone xmissions during this event. Aircraft was pushed back from gate using standard phraseology (from what I could hear in the cockpit). Captain acknowledged cleared to start engines and directed first officer to start engines. First officer proceeded to start engines as aircraft was moving rearward. During rearward movement captain attempted to call push crew on interphone and with crew call button multiple times and was apparently getting no response. During this period, rearward movement stopped followed by noise and some lurching from the area of the nose gear. Noise was not typical 'clunking' associated with towbar removal, but seemed more to be associated with repositioning of the tug. The aircraft then began to roll forward and I assumed we were being towed forward by the push crew. Nevertheless, something didn't seem quite right and all 3 crew members attempted to look over nose to verify that tug was still connected. At about that time, both the captain and I saw tug in our peripheral vision moving away from left side of aircraft. Captain immediately applied brakes and push crew walked back to airplane to reconnect. Captain inquired about what happened and relayed to me that push crew said they had lost communication with cockpit and that a shear pin on the towbar had snapped. Captain and first officer summoned maintenance to inspect nose gear. Maintenance inspected nose gear and observed no damage. Maintenance told captain that based on discussion with push crew, it appeared that 1 ramp service person misunderstood the other and disconnected towbar from aircraft without being directed to do so. They said there was no damage to towbar either. I estimate aircraft rolled 10 ft forward after disconnection and stopped with left engine nacelle approximately 20 ft from tug. Although push crew apparently did an excellent job of getting tug and personnel out of the way quickly, there was obvious miscom between the push crew on the ramp compounded by loss of contact with the cockpit. At no time did I observe ground crew use hand signals following loss of communication. Flight proceeded uneventfully to ZZZ. Callback conversation with reporter revealed the following information: the reporter stated position in the cockpit was as an observer member of crew and also acted as the carrier safety officer. The reporter said all of the standard operating pushback safety procedures were not observed. The reporter stated the first officer was distraction with starting engines during the pushback believing the captain wanted both engines started when the captain ordered only the left engine started. The reporter stated this had the first officer distraction with engine scan. The reporter said the captain was trying to establish contact with the ground crew and activating the crew call with no success. The reporter stated ground crew disconnected the towbar without the tug operator giving clearance and aircraft brakes were not set. The reporter said fortunately the tug moved away from the airplane and the airplane rolled forward uncontrolled. The reporter stated at no time were any hand signals used to alert the cockpit during the loss of the ground interphone. The reporter said the pushback is being done by ramp service people and they need much more training to become proficient and safe. Supplemental information from acn 614429: I need to pay more attention to how many engines the captain commands for the start. Other issues include how much of an outside scan I need to have during the pushback, but I still believe my primary scan should be the engine instruments.

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Original NASA ASRS Text

Title: AN A320 FLT CREW, DURING PUSHBACK AND WHILE STOPPED, RPTED THE TOWBAR HAD BEEN DISCONNECTED BY THE GND CREW WITHOUT CLRNC. THE ACFT THEN ROLLED FORWARD.

Narrative: I WAS ON THIS FLT, SEATED IN THE COCKPIT JUMP SEAT, AND WAS NOT MONITORING RADIO OR INTERPHONE XMISSIONS DURING THIS EVENT. ACFT WAS PUSHED BACK FROM GATE USING STANDARD PHRASEOLOGY (FROM WHAT I COULD HEAR IN THE COCKPIT). CAPT ACKNOWLEDGED CLRED TO START ENGS AND DIRECTED FO TO START ENGS. FO PROCEEDED TO START ENGS AS ACFT WAS MOVING REARWARD. DURING REARWARD MOVEMENT CAPT ATTEMPTED TO CALL PUSH CREW ON INTERPHONE AND WITH CREW CALL BUTTON MULTIPLE TIMES AND WAS APPARENTLY GETTING NO RESPONSE. DURING THIS PERIOD, REARWARD MOVEMENT STOPPED FOLLOWED BY NOISE AND SOME LURCHING FROM THE AREA OF THE NOSE GEAR. NOISE WAS NOT TYPICAL 'CLUNKING' ASSOCIATED WITH TOWBAR REMOVAL, BUT SEEMED MORE TO BE ASSOCIATED WITH REPOSITIONING OF THE TUG. THE ACFT THEN BEGAN TO ROLL FORWARD AND I ASSUMED WE WERE BEING TOWED FORWARD BY THE PUSH CREW. NEVERTHELESS, SOMETHING DIDN'T SEEM QUITE RIGHT AND ALL 3 CREW MEMBERS ATTEMPTED TO LOOK OVER NOSE TO VERIFY THAT TUG WAS STILL CONNECTED. AT ABOUT THAT TIME, BOTH THE CAPT AND I SAW TUG IN OUR PERIPHERAL VISION MOVING AWAY FROM L SIDE OF ACFT. CAPT IMMEDIATELY APPLIED BRAKES AND PUSH CREW WALKED BACK TO AIRPLANE TO RECONNECT. CAPT INQUIRED ABOUT WHAT HAPPENED AND RELAYED TO ME THAT PUSH CREW SAID THEY HAD LOST COM WITH COCKPIT AND THAT A SHEAR PIN ON THE TOWBAR HAD SNAPPED. CAPT AND FO SUMMONED MAINT TO INSPECT NOSE GEAR. MAINT INSPECTED NOSE GEAR AND OBSERVED NO DAMAGE. MAINT TOLD CAPT THAT BASED ON DISCUSSION WITH PUSH CREW, IT APPEARED THAT 1 RAMP SVC PERSON MISUNDERSTOOD THE OTHER AND DISCONNECTED TOWBAR FROM ACFT WITHOUT BEING DIRECTED TO DO SO. THEY SAID THERE WAS NO DAMAGE TO TOWBAR EITHER. I ESTIMATE ACFT ROLLED 10 FT FORWARD AFTER DISCONNECTION AND STOPPED WITH L ENG NACELLE APPROX 20 FT FROM TUG. ALTHOUGH PUSH CREW APPARENTLY DID AN EXCELLENT JOB OF GETTING TUG AND PERSONNEL OUT OF THE WAY QUICKLY, THERE WAS OBVIOUS MISCOM BTWN THE PUSH CREW ON THE RAMP COMPOUNDED BY LOSS OF CONTACT WITH THE COCKPIT. AT NO TIME DID I OBSERVE GND CREW USE HAND SIGNALS FOLLOWING LOSS OF COM. FLT PROCEEDED UNEVENTFULLY TO ZZZ. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED POS IN THE COCKPIT WAS AS AN OBSERVER MEMBER OF CREW AND ALSO ACTED AS THE CARRIER SAFETY OFFICER. THE RPTR SAID ALL OF THE STANDARD OPERATING PUSHBACK SAFETY PROCS WERE NOT OBSERVED. THE RPTR STATED THE FO WAS DISTR WITH STARTING ENGS DURING THE PUSHBACK BELIEVING THE CAPT WANTED BOTH ENGS STARTED WHEN THE CAPT ORDERED ONLY THE L ENG STARTED. THE RPTR STATED THIS HAD THE FO DISTR WITH ENG SCAN. THE RPTR SAID THE CAPT WAS TRYING TO ESTABLISH CONTACT WITH THE GND CREW AND ACTIVATING THE CREW CALL WITH NO SUCCESS. THE RPTR STATED GND CREW DISCONNECTED THE TOWBAR WITHOUT THE TUG OPERATOR GIVING CLRNC AND ACFT BRAKES WERE NOT SET. THE RPTR SAID FORTUNATELY THE TUG MOVED AWAY FROM THE AIRPLANE AND THE AIRPLANE ROLLED FORWARD UNCTLED. THE RPTR STATED AT NO TIME WERE ANY HAND SIGNALS USED TO ALERT THE COCKPIT DURING THE LOSS OF THE GND INTERPHONE. THE RPTR SAID THE PUSHBACK IS BEING DONE BY RAMP SVC PEOPLE AND THEY NEED MUCH MORE TRAINING TO BECOME PROFICIENT AND SAFE. SUPPLEMENTAL INFO FROM ACN 614429: I NEED TO PAY MORE ATTN TO HOW MANY ENGS THE CAPT COMMANDS FOR THE START. OTHER ISSUES INCLUDE HOW MUCH OF AN OUTSIDE SCAN I NEED TO HAVE DURING THE PUSHBACK, BUT I STILL BELIEVE MY PRIMARY SCAN SHOULD BE THE ENG INSTS.

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.