 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
The B737-200 coach seat pan repair procedure was discovered to be undocumented with no published fastener edge-to-edge hole limits.
| Attributes | |
| ACN | 614736 |
| Time | |
| Date | 200404 |
| Day | Sat |
| Place | |
| Locale Reference | airport : zzz.airport |
| State Reference | US |
| Altitude | agl single value : 0 |
| Aircraft 1 | |
| Operator | common carrier : air carrier |
| Make Model Name | B737-200 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | ground : maintenance |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | maintenance : technician |
| ASRS Report | 614736 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | maintenance : technician |
| ASRS Report | 614737 |
| Events | |
| Anomaly | aircraft equipment problem : less severe maintenance problem : improper documentation non adherence : far non adherence : published procedure |
| Resolutory Action | none taken : detected after the fact |
| Consequence | other other Other |
| Supplementary | |
| Problem Areas | Aircraft Chart Or Publication Company Maintenance Human Performance |
| Primary Problem | Chart Or Publication |
| Situations | |
| Publication | Maint Manual |
Narrative:
When installing new seat pans with previous holes in support tubes, it was common practice to move the seat pan to the right or left so when installing new fasteners you would have the proper distance between old holes and new holes. On any seat pans I installed where an old pan had been removed, I always made sure I had plenty of new material (at least 2D rivet spacing) prior to drilling new holes and installing the new fasteners. Again at this time, this was common practice when doing this job. Supplemental information from acn 614739: this action was performed by all who worked in the seat shop while I was there, and it was also known to and approved by inspection at that time. Supplemental information from acn 615012: inspection found that repair technicians were repairing loose seat diaphragms by removing diaphragms to rivets and relocating same on seat support tubes. Further investigation revealed many previously repaired seats with double-drilled or drilled with poor edge margin seat tubes.
Original NASA ASRS Text
Title: THE B737-200 COACH SEAT PAN REPAIR PROC WAS DISCOVERED TO BE UNDOCUMENTED WITH NO PUBLISHED FASTENER EDGE-TO-EDGE HOLE LIMITS.
Narrative: WHEN INSTALLING NEW SEAT PANS WITH PREVIOUS HOLES IN SUPPORT TUBES, IT WAS COMMON PRACTICE TO MOVE THE SEAT PAN TO THE R OR L SO WHEN INSTALLING NEW FASTENERS YOU WOULD HAVE THE PROPER DISTANCE BTWN OLD HOLES AND NEW HOLES. ON ANY SEAT PANS I INSTALLED WHERE AN OLD PAN HAD BEEN REMOVED, I ALWAYS MADE SURE I HAD PLENTY OF NEW MATERIAL (AT LEAST 2D RIVET SPACING) PRIOR TO DRILLING NEW HOLES AND INSTALLING THE NEW FASTENERS. AGAIN AT THIS TIME, THIS WAS COMMON PRACTICE WHEN DOING THIS JOB. SUPPLEMENTAL INFO FROM ACN 614739: THIS ACTION WAS PERFORMED BY ALL WHO WORKED IN THE SEAT SHOP WHILE I WAS THERE, AND IT WAS ALSO KNOWN TO AND APPROVED BY INSPECTION AT THAT TIME. SUPPLEMENTAL INFO FROM ACN 615012: INSPECTION FOUND THAT REPAIR TECHNICIANS WERE REPAIRING LOOSE SEAT DIAPHRAGMS BY REMOVING DIAPHRAGMS TO RIVETS AND RELOCATING SAME ON SEAT SUPPORT TUBES. FURTHER INVESTIGATION REVEALED MANY PREVIOUSLY REPAIRED SEATS WITH DOUBLE-DRILLED OR DRILLED WITH POOR EDGE MARGIN SEAT TUBES.
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.