Three mechanics report about a B767-300 nose gear axle nut washer that was not reinstalled during a nose tire change he had accomplished with another Mechanic. The mechanics found the axle nut washer the following day; still stuck in the grease on the wheel rim of the removed tire.
Synopsis
Three mechanics report about a B767-300 nose gear axle nut washer that was not reinstalled during a nose tire change he had accomplished with another Mechanic. The mechanics found the axle nut washer the following day; still stuck in the grease on the wheel rim of the removed tire.
Narrative
After working a B777 aircraft from the start of the shift that was going to be leaving that evening; we had a Service Check; logbook items; as well as deferrals to accomplish. We; Mechanic 'Y' and I; wanted to finish the aircraft before we ate dinner. While eating dinner we were told that a nose tire needed to be changed on a B767-300 aircraft that was on the ramp and it needed to be done soon because the aircraft was needed for a trip. We finished eating; went to get all the equipment for changing the tire and found out the ramp was moving the aircraft to a different terminal for departure. We met the aircraft when it got there. The jetway [electrical] power was not working; so right off the bat we were trying to work with ramp on getting them out of way so we could get the [nose] tire done. Once the ramp was out of the way; we started to work; removed the tire and waited for the Supervisor to check the backup spacer. When the Supervisor showed up; so did ramp with a power unit and they wanted us to move our equipment. We were trying to finish our job and had to stop to move equipment. The Supervisor checked the spacer and Mechanic 'Y' and I installed the tire. While we were doing this; the ramp was still having trouble and we just told them to move the power unit off to the side and wait until we were finished. We installed the tire with everything that came off and did not notice the axle nut washer was missing; applied the [initial] torque and the wheel nut torqued as per the paperwork. I spun the tire and Mechanic 'Y' torqued. We finished the job and got out of everyones way; so that the aircraft could get ready for its departure.The next day was when we found out we had missed the washer when we had another aircraft coming from ZZZ1 without a washer on a nosewheel. Mechanic 'Y' called me to ask about the washer. I didn't recall putting it on and neither did he; so we checked the removed nose tire and the washer was stuck in the grease on the rim; you could hardly see it until you looked for it. This was when we notified the Supervisor and Leads [of our incident] and filled out a report.
NASA callback
Reporter stated the B767-300 that arrived from ZZZ1 was not the same B767 they had worked on the previous day. But the issue was the same. Mechanics in ZZZ1 had not reinstalled the axle washer on the left nose tire. A Mechanic working the Tire Shop in ZZZ1 had noticed the axle washer stuck to the grease on the wheel rim and quickly informed the mechanics who had changed the tire in ZZZ1; but the aircraft had just taken off; headed for Reporter's station; that's when he and his work partner from the previous day decided to check the left nose tire they had removed from the B767-300. Reporter stated the axle wheel nut can still be properly torqued even without the axle nut washer installed; because the nut does not bottom out when the washer is missing. When the washer is installed; approximately two and a half to three axle threads will be exposed on the externally threaded nose axle; as compared to five threads showing when the washer is not installed.Reporter stated one of their company mechanics at a different Maintenance Station had recently come up with a type of socket that could be used to tighten and torque the nose gear axle nut on the B767; only if the axle washer was installed. That socket is shallower; less deep than the socket they currently use to install and torque the axle nut with. His station does not have that socket yet. They do have a similar type of socket for the B757 and B767 main gear tire axle nuts. Their supervisors now have to view not only the inboard wheel spacer being installed; but the outboard axle washer as well.
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Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.