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A B757-200 was discovered to have operated for 2 days with either a right nose tire worn bearing or the incorrect bearing installed at wheel shop.
| Attributes | |
| ACN | 495608 |
| Time | |
| Date | 200012 |
| Day | Sun |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : zzz.airport |
| State Reference | US |
| Altitude | agl single value : 0 |
| Environment | |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tower : sfo.tower |
| Operator | common carrier : air carrier |
| Make Model Name | B757-200 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | ground : maintenance ground : parked |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | maintenance : technician |
| Qualification | technician : airframe technician : powerplant |
| Experience | maintenance avionics : 10 maintenance repairman : 7 maintenance technician : 1 |
| ASRS Report | 495608 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | maintenance : lead technician |
| Qualification | technician : airframe technician : powerplant |
| Events | |
| Anomaly | aircraft equipment problem : critical maintenance problem : improper maintenance non adherence : far non adherence : published procedure |
| Resolutory Action | none taken : detected after the fact |
| Consequence | other other |
| Factors | |
| Maintenance | contributing factor : schedule pressure performance deficiency : inspection performance deficiency : installation |
| Supplementary | |
| Problem Areas | Aircraft Maintenance Human Performance |
| Primary Problem | Maintenance Human Performance |
Narrative:
On dec/xa/00, at ZZZ, I replaced the nosewheel and tire, right side, because it was showing cord per the maintenance manual. I properly torqued the axle nut and installed the 2 lock bolts. I believe this was after flight number XXX. On dec/xc/00 at abc, they wrote up 'nosewheel axle nut assembly does not look proper, no threads showing first officer side.' the corrective action was 'found bearing worn, replaced right nosewheel assembly per maintenance manual.' what I don't understand is, if the wheel/tire assembly was improperly installed, how could the 2 lock bolts be installed? I did rotate the tire while torquing the axle nut. The only thing I can think of is maybe the incorrect bearing was installed on the wheel or a worn bearing. However, I saw nothing wrong with it during installation.
Original NASA ASRS Text
Title: A B757-200 WAS DISCOVERED TO HAVE OPERATED FOR 2 DAYS WITH EITHER A R NOSE TIRE WORN BEARING OR THE INCORRECT BEARING INSTALLED AT WHEEL SHOP.
Narrative: ON DEC/XA/00, AT ZZZ, I REPLACED THE NOSEWHEEL AND TIRE, R SIDE, BECAUSE IT WAS SHOWING CORD PER THE MAINT MANUAL. I PROPERLY TORQUED THE AXLE NUT AND INSTALLED THE 2 LOCK BOLTS. I BELIEVE THIS WAS AFTER FLT NUMBER XXX. ON DEC/XC/00 AT ABC, THEY WROTE UP 'NOSEWHEEL AXLE NUT ASSEMBLY DOES NOT LOOK PROPER, NO THREADS SHOWING FO SIDE.' THE CORRECTIVE ACTION WAS 'FOUND BEARING WORN, REPLACED R NOSEWHEEL ASSEMBLY PER MAINT MANUAL.' WHAT I DON'T UNDERSTAND IS, IF THE WHEEL/TIRE ASSEMBLY WAS IMPROPERLY INSTALLED, HOW COULD THE 2 LOCK BOLTS BE INSTALLED? I DID ROTATE THE TIRE WHILE TORQUING THE AXLE NUT. THE ONLY THING I CAN THINK OF IS MAYBE THE INCORRECT BEARING WAS INSTALLED ON THE WHEEL OR A WORN BEARING. HOWEVER, I SAW NOTHING WRONG WITH IT DURING INSTALLATION.
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.