37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
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Attributes | |
ACN | 614741 |
Time | |
Date | 200404 |
Day | Tue |
Local Time Of Day | 0601 To 1200 |
Place | |
Locale Reference | airport : zzz.airport |
State Reference | US |
Altitude | agl single value : 0 |
Aircraft 1 | |
Operator | common carrier : air carrier |
Make Model Name | B767-200 |
Operating Under FAR Part | Part 121 |
Flight Phase | ground : maintenance |
Person 1 | |
Affiliation | company : air carrier |
Function | maintenance : lead technician |
Experience | maintenance lead technician : 3 maintenance technician : 13 |
ASRS Report | 614741 |
Person 2 | |
Affiliation | company : air carrier |
Function | maintenance : technician |
Events | |
Anomaly | aircraft equipment problem : critical maintenance problem : improper maintenance maintenance problem : improper documentation non adherence : published procedure non adherence : company policies non adherence : far |
Independent Detector | aircraft equipment other aircraft equipment : lndg gear position indication other flight crewa other flight crewb |
Resolutory Action | flight crew : diverted to another airport flight crew : declared emergency flight crew : overcame equipment problem |
Consequence | other other |
Factors | |
Maintenance | contributing factor : work cards contributing factor : manuals performance deficiency : logbook entry performance deficiency : installation performance deficiency : non compliance with legal requirements performance deficiency : testing performance deficiency : inspection |
Supplementary | |
Problem Areas | Maintenance Human Performance Chart Or Publication Aircraft |
Primary Problem | Maintenance Human Performance |
Narrative:
I was assigned the task of repack on a B767 main landing gear repack. I had paperwork out at the airplane. I removed the lower truck assembly, removed all parts and began assembly. I found our paper confusing, but was able to press on with the job (paperwork confusion consisted of pre PEA32100002 and post PEA32100002 and fluid interchangeability. We normally used casterlero 40, but we did not have any and in the amm suitable replacement for casterlero was found and I pressed on). We assembled the lower gland nut, lower seal carrier, spacer, snubber and upper bearing. The upper bearing can be assembled about 5 different ways. It is not murphy proof. The amm says to check for proper orientation, and this is where I made the mistake. I was fixated on the orientation (installed either upside down or right side up) and not the proper placement of the upper bearing. We continued on and finished the repack and I signed the paperwork off. En route to destination, the crew discovered the r-hand main landing gear would not come out of the wheel well. They declared an emergency and through extreme maneuvers were able to free the gear and land safely. I was called out to fly to base to perform another strut repack and found we had assembled the upper bearing incorrectly. The company has now put in place procedures to prevent such an incident from happening again such as the use of a job card with a strut measurement and inspector buy-back and mandatory gear swings. There is no warning in the amm that stresses the importance of bearing placement. The strut over-extended by 7/8 inch and got caught on the hook in the wheel well. Callback conversation with reporter revealed the following information: the reporter stated the upper bearing was installed incorrectly and resulted in the landing gear strut extending .875 inch longer interfering and catching on the uplock hook. The reporter said the upper bearing illustrations and written procedures were confusing and really very little about a part that can be installed 5 different ways and is certainly not murphy proof. The reporter stated the carrier now has revised the maintenance manual and job cards for the strut buildup and requires a gear swing and inspector strut measurement. The reporter said the manual also requires an rii inspection.
Original NASA ASRS Text
Title: A B767-200 CREW DECLARED AN EMER AND DIVERTED DUE TO UNABLE TO EXTEND THE R MAIN LNDG GEAR. CAUSED BY INCORRECT ASSEMBLY OF THE STRUT. EXTREME MANEUVERS REQUIRED TO FREE GEAR.
Narrative: I WAS ASSIGNED THE TASK OF REPACK ON A B767 MAIN LNDG GEAR REPACK. I HAD PAPERWORK OUT AT THE AIRPLANE. I REMOVED THE LOWER TRUCK ASSEMBLY, REMOVED ALL PARTS AND BEGAN ASSEMBLY. I FOUND OUR PAPER CONFUSING, BUT WAS ABLE TO PRESS ON WITH THE JOB (PAPERWORK CONFUSION CONSISTED OF PRE PEA32100002 AND POST PEA32100002 AND FLUID INTERCHANGEABILITY. WE NORMALLY USED CASTERLERO 40, BUT WE DID NOT HAVE ANY AND IN THE AMM SUITABLE REPLACEMENT FOR CASTERLERO WAS FOUND AND I PRESSED ON). WE ASSEMBLED THE LOWER GLAND NUT, LOWER SEAL CARRIER, SPACER, SNUBBER AND UPPER BEARING. THE UPPER BEARING CAN BE ASSEMBLED ABOUT 5 DIFFERENT WAYS. IT IS NOT MURPHY PROOF. THE AMM SAYS TO CHK FOR PROPER ORIENTATION, AND THIS IS WHERE I MADE THE MISTAKE. I WAS FIXATED ON THE ORIENTATION (INSTALLED EITHER UPSIDE DOWN OR RIGHT SIDE UP) AND NOT THE PROPER PLACEMENT OF THE UPPER BEARING. WE CONTINUED ON AND FINISHED THE REPACK AND I SIGNED THE PAPERWORK OFF. ENRTE TO DEST, THE CREW DISCOVERED THE R-HAND MAIN LNDG GEAR WOULD NOT COME OUT OF THE WHEEL WELL. THEY DECLARED AN EMER AND THROUGH EXTREME MANEUVERS WERE ABLE TO FREE THE GEAR AND LAND SAFELY. I WAS CALLED OUT TO FLY TO BASE TO PERFORM ANOTHER STRUT REPACK AND FOUND WE HAD ASSEMBLED THE UPPER BEARING INCORRECTLY. THE COMPANY HAS NOW PUT IN PLACE PROCS TO PREVENT SUCH AN INCIDENT FROM HAPPENING AGAIN SUCH AS THE USE OF A JOB CARD WITH A STRUT MEASUREMENT AND INSPECTOR BUY-BACK AND MANDATORY GEAR SWINGS. THERE IS NO WARNING IN THE AMM THAT STRESSES THE IMPORTANCE OF BEARING PLACEMENT. THE STRUT OVER-EXTENDED BY 7/8 INCH AND GOT CAUGHT ON THE HOOK IN THE WHEEL WELL. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE UPPER BEARING WAS INSTALLED INCORRECTLY AND RESULTED IN THE LNDG GEAR STRUT EXTENDING .875 INCH LONGER INTERFERING AND CATCHING ON THE UPLOCK HOOK. THE RPTR SAID THE UPPER BEARING ILLUSTRATIONS AND WRITTEN PROCS WERE CONFUSING AND REALLY VERY LITTLE ABOUT A PART THAT CAN BE INSTALLED 5 DIFFERENT WAYS AND IS CERTAINLY NOT MURPHY PROOF. THE RPTR STATED THE CARRIER NOW HAS REVISED THE MAINT MANUAL AND JOB CARDS FOR THE STRUT BUILDUP AND REQUIRES A GEAR SWING AND INSPECTOR STRUT MEASUREMENT. THE RPTR SAID THE MANUAL ALSO REQUIRES AN RII INSPECTION.
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.