Narrative:

Several passenger seats came loose after A320 aircraft was returned to service following a heavy maintenance visit. The problem arose from the seat locking device not being properly locked into the aircraft seat track. Seats were discovered loose by passenger in-flight. Seats were re-secured after aircraft returned to the gate and released for service. The paperwork and manuals involved with this job were not specific about making sure positive engagement of lock was accomplished. They only called out for torquing lock screw to a specific torque value. The lock screw can be torqued even if locking device is not properly engaged. A red band around locking device would assist in determining a positive engagement of locking device into aircraft seat track. Also having paperwork which covered one specific task instead of multiple tasks would be less confusing. Callback conversation with reporter revealed the following information: the reporter stated the seat installation was accomplished per the air carrier job cards and were inspected after the work was completed. The reporter said the air carrier job card is made complex by adding other tasks such as emergency escape lighting, in-flight entertainment, emergency oxygen, and lighting seat to seat cables. The reporter said references and drawings are complicated and confusing due to improper indication of the latest revisions. The reporter said the airbus maintenance manual reference on seat installations is confusing with parts with figure numbers that are referenced with no figure diagram for the A320. The reporter said no information is given on torque values, methods or tooling required. The reporter stated the seat manufacturer's overhaul manual gives no procedures for proper seat installation and no tooling to accomplish the final torque. The reporter said the method used to tighten the seat locks due to a lack of proper tooling is a drift punch and a hammer. The reporter stated the air carrier is taking action to correct the deficiencies as soon as possible.

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Original NASA ASRS Text

Title: AN AIRBUS 320 WAS DISPATCHED AND RETURNED TO THE FIELD DUE TO 12 PAX SEATS NOT SECURED IN THE SEAT TRACKS CAUSED BY IMPROPER INSTALLATION INSTRUCTIONS AND PROCS.

Narrative: SEVERAL PAX SEATS CAME LOOSE AFTER A320 ACFT WAS RETURNED TO SVC FOLLOWING A HVY MAINT VISIT. THE PROB AROSE FROM THE SEAT LOCKING DEVICE NOT BEING PROPERLY LOCKED INTO THE ACFT SEAT TRACK. SEATS WERE DISCOVERED LOOSE BY PAX INFLT. SEATS WERE RE-SECURED AFTER ACFT RETURNED TO THE GATE AND RELEASED FOR SVC. THE PAPERWORK AND MANUALS INVOLVED WITH THIS JOB WERE NOT SPECIFIC ABOUT MAKING SURE POSITIVE ENGAGEMENT OF LOCK WAS ACCOMPLISHED. THEY ONLY CALLED OUT FOR TORQUING LOCK SCREW TO A SPECIFIC TORQUE VALUE. THE LOCK SCREW CAN BE TORQUED EVEN IF LOCKING DEVICE IS NOT PROPERLY ENGAGED. A RED BAND AROUND LOCKING DEVICE WOULD ASSIST IN DETERMINING A POSITIVE ENGAGEMENT OF LOCKING DEVICE INTO ACFT SEAT TRACK. ALSO HAVING PAPERWORK WHICH COVERED ONE SPECIFIC TASK INSTEAD OF MULTIPLE TASKS WOULD BE LESS CONFUSING. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE SEAT INSTALLATION WAS ACCOMPLISHED PER THE ACR JOB CARDS AND WERE INSPECTED AFTER THE WORK WAS COMPLETED. THE RPTR SAID THE ACR JOB CARD IS MADE COMPLEX BY ADDING OTHER TASKS SUCH AS EMER ESCAPE LIGHTING, INFLT ENTERTAINMENT, EMER OXYGEN, AND LIGHTING SEAT TO SEAT CABLES. THE RPTR SAID REFS AND DRAWINGS ARE COMPLICATED AND CONFUSING DUE TO IMPROPER INDICATION OF THE LATEST REVISIONS. THE RPTR SAID THE AIRBUS MAINT MANUAL REF ON SEAT INSTALLATIONS IS CONFUSING WITH PARTS WITH FIGURE NUMBERS THAT ARE REFED WITH NO FIGURE DIAGRAM FOR THE A320. THE RPTR SAID NO INFO IS GIVEN ON TORQUE VALUES, METHODS OR TOOLING REQUIRED. THE RPTR STATED THE SEAT MANUFACTURER'S OVERHAUL MANUAL GIVES NO PROCS FOR PROPER SEAT INSTALLATION AND NO TOOLING TO ACCOMPLISH THE FINAL TORQUE. THE RPTR SAID THE METHOD USED TO TIGHTEN THE SEAT LOCKS DUE TO A LACK OF PROPER TOOLING IS A DRIFT PUNCH AND A HAMMER. THE RPTR STATED THE ACR IS TAKING ACTION TO CORRECT THE DEFICIENCIES AS SOON AS POSSIBLE.

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.