B767-400 and 400 ER
Maintenance Powerplant; Maintenance Airframe
Maintenance Technician 23
Time Pressure; Workload; Situational Awareness; Distraction
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Aircraft; Weather; Staffing; Incorrect / Not Installed / Unavailable Part; Human Factors; Company Policy
A B767 aircraft arrived at one of the gates after a Super Tug move from another gate. Upon arrival; a large gash approximately ten inches long was found in the center tread of the left nose tire. The airplane arrived at my gate during a very heavy period of international departures. I had been working on another aircraft in the area; when I was instructed to go and change the tire in question as well as work two open logbook items on clogged galley drains and a clogged sink drain. I had about 30 minutes to accomplish the tasks.I don't remember taking a wheel spacer off of the old tire; so it may not have been present to reinstall. I installed the new tire and torqued the nut to the appropriate values. There was no excessive play in the wheel assembly and the threads looked normal for a nose tire axle nut. I signed the logbook off at departure time and went to work another aircraft. It was a hot day. I had had a very challenging afternoon working on other aircraft earlier in the shift; the workload was very heavy; we are currently six Aircraft Maintenance Technicians (AMT)s short on international at this station; and I hadn't changed a nose tire in quite some time. I believe all of these to be factors in missing the wheel spacer.
Reporter stated there are two types of B767 Nose Landing Gear (NLG) axles in their fleet. One model has an internally threaded NLG axle which does not require a spacer; but the externally threaded type does. The B767 had flown three flight legs prior to a company Line Mechanic noticing the difference at one of their Stations. The wheel spacer was not missing but the axle nut washer was. He still doesn't know how the Line Mechanic recognized there was anything unusual with the previous nose tire installation.
The left nose tire assembly previously replaced on a B767 aircraft was missing an axle nut washer.