Narrative:

After an uneventful flight; we taxied to the gate. We shut down engine #2 prior to taxiing to the gate. Upon arrival; I set the parking brake; waited for the ground power sign; and then shut down engine #1. The ramp agent gave us the chocks-in sign and the parking brake was released. I waited a few seconds and then focused my attention to cleaning up the cockpit as we had a crew change. About 15-20 seconds later I heard a pounding on the side of the aircraft and shouting coming from the jetway. The cabin door had already been opened and the jetway brought to the aircraft. At that point I noticed the aircraft moving backwards and slammed on the brakes. The aircraft had traveled about 5-8 ft where the cabin door came in contact with the jetway; puncturing a hole in the jetway; snapping the cabin door upper gust lock hinge and also damaged the lower right inside of the cabin door. The outbound first officer; who was conducting his walkaround; informed us the ramp agents were walking away from the aircraft after shutdown and that the aircraft did not begin to move until 15-20 seconds after shutdown. Subsequently; the aircraft was pulled forward so passenger could deplane. It was confirmed by outbound first officer that the chocks were never inserted. I would highly recommend that the company reconsider its non-use of the parking brake while at the gate after shutdown.

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Original NASA ASRS Text

Title: B737-300 WAS PARKED AT GATE AND ENGS SHUT DOWN. ACFT BEGAN ROLLING BACKWARD AS A RESULT OF CHOCKS NOT INSTALLED PER COMPANY SOP.

Narrative: AFTER AN UNEVENTFUL FLT; WE TAXIED TO THE GATE. WE SHUT DOWN ENG #2 PRIOR TO TAXIING TO THE GATE. UPON ARR; I SET THE PARKING BRAKE; WAITED FOR THE GND PWR SIGN; AND THEN SHUT DOWN ENG #1. THE RAMP AGENT GAVE US THE CHOCKS-IN SIGN AND THE PARKING BRAKE WAS RELEASED. I WAITED A FEW SECONDS AND THEN FOCUSED MY ATTN TO CLEANING UP THE COCKPIT AS WE HAD A CREW CHANGE. ABOUT 15-20 SECONDS LATER I HEARD A POUNDING ON THE SIDE OF THE ACFT AND SHOUTING COMING FROM THE JETWAY. THE CABIN DOOR HAD ALREADY BEEN OPENED AND THE JETWAY BROUGHT TO THE ACFT. AT THAT POINT I NOTICED THE ACFT MOVING BACKWARDS AND SLAMMED ON THE BRAKES. THE ACFT HAD TRAVELED ABOUT 5-8 FT WHERE THE CABIN DOOR CAME IN CONTACT WITH THE JETWAY; PUNCTURING A HOLE IN THE JETWAY; SNAPPING THE CABIN DOOR UPPER GUST LOCK HINGE AND ALSO DAMAGED THE LOWER R INSIDE OF THE CABIN DOOR. THE OUTBOUND FO; WHO WAS CONDUCTING HIS WALKAROUND; INFORMED US THE RAMP AGENTS WERE WALKING AWAY FROM THE ACFT AFTER SHUTDOWN AND THAT THE ACFT DID NOT BEGIN TO MOVE UNTIL 15-20 SECONDS AFTER SHUTDOWN. SUBSEQUENTLY; THE ACFT WAS PULLED FORWARD SO PAX COULD DEPLANE. IT WAS CONFIRMED BY OUTBOUND FO THAT THE CHOCKS WERE NEVER INSERTED. I WOULD HIGHLY RECOMMEND THAT THE COMPANY RECONSIDER ITS NON-USE OF THE PARKING BRAKE WHILE AT THE GATE AFTER SHUTDOWN.

Data retrieved from NASA's ASRS site as of January 2009 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.