Two line mechanics were informed a contract tire repair shop Mechanic found an axle nut washer stuck to the wheel bearing race of a nose tire they had removed from a B767-300 approximately one week earlier.
Synopsis
Two line mechanics were informed a contract tire repair shop Mechanic found an axle nut washer stuck to the wheel bearing race of a nose tire they had removed from a B767-300 approximately one week earlier.
Narrative
Arrived at work as usual approximately XA:15am. Walked from parking lot to [gate] Maintenance area. Checked daily assignment sheet; company e-mail; and Routine Overnight (RON) aircraft. I was assigned several gates that day. Our normal start time is XC:00am. A B767-300 charter Flight from ZZZ-ZZZ1-ZZZ2 arrived approximately XB:40am and was scheduled to depart ZZZ1 at XE:00am. The weather was beautiful; cool; a bright sunny morning. I was a member of a three person team assigned to 'turn' the B767; I am not trained on the B767 but the other members were qualified. We proceeded to the aircraft. I started the visual walk around of the aircraft while the other members did servicing tasks for the [aircraft] turn. Deep cuts; beyond the Maintenance Manual (M/M) limits; were noted on the number 7 Main tire and the left nose tire. The tires were ordered; someone brought the tire change cart; and printed the Maintenance Manual references. We replaced the number 7 main wheel assembly first; that completed; we moved to the left nose wheel assembly. At this point we noticed the flight information screen at the gate had a revised departure time of XD:00am instead of XE:00am; but no one notified us so we thought we had lost one hour of time and felt the constraint.I remember someone jacking the nose; I removed the locking hardware and axle nut. Coworkers removed the wheel assembly from the axle and installed a serviceable [tire] assembly on the axle. My coworkers visually checked the wheel assembly installation and compared it to the right nose wheel assembly; all appeared normal to them. I did not visually check for the spacer since I was installing the washer and axle nut at the time. We torqued the assembly; torquing up was normal and I installed the safety bolts. Before letting the [aircraft]jack down; I performed a 'wobble' check; all was fine. The gate mounted air conditioning system for the aircraft was running right next to us and it is very loud. For several of us this was the first B767 tire assembly we had ever changed. The Logbook was completed and the aircraft departed after its original time of XE:00am; well after our work was completed.The B767-300 flew its flight and a week later a spacer was noted with the tire assembly at the [tire] shop in ZZZ3. They notified Maintenance Control and the aircraft was tracked [located] at ZZZ4. The mechanics in ZZZ4 inspected the left nose wheel installation and noted the left nose tire spacer was missing so a replacement spacer and wheel assembly were installed. The aircraft flew without incident during the time the spacer was out and no damage was reported.What went wrong/fix: Aviation Maintenance Technician (AMT) should have physically touched the [nose wheel axle] spacer to ensure of it's installation. In retrospect; I should have specifically asked if the spacer was installed because the Maintenance Manual (M/M) notes that the spacer needs to be installed several times. We should have checked each other. We were unfamiliar with the task; although not rushed; we felt the time constraints on this high profile flight. The company should have ensured enough qualified people available. Given our experience level this should not have occurred. I should have not taken the other members word the installation was correct and checked it myself.Although I did not sign for the work; I was present and do feel the affects of the incident mentally. Other departments could have done better: Ramp Control should have verbally kept us informed of any changes to the flight status and departure time changes; this policy was in place several years ago but not now. It should be reinstated. Through other sources; this problem with the spacer has occurred many times prior to this incident. If it's a continual issue; either the manufacturer or the company should address why the spacer comes off the axle so easily and engineer a tighter tolerance or security system that will keep the [wheel/tire] assembly from torquing up properly if the spacer is not installed. Or; [design] the safety bolts [so they] will not install [if spacer is missing]; sort of a fool proof installation process.Final thoughts: each member of the team involved in this incident has over 30-years experience with the company; are very good and dedicated mechanics. This oversight has affected each of us deeply and has increased our awareness during team Maintenance efforts.
Second reporter narrative
Three of us mechanics were changing a nose tire on a B767-300 aircraft. I jacked the airplane and lowered it. We inspected the old wheel and new wheel inside bearing surface before installation; it looked identical. We had the Maintenance Manual (M/M) with us. There is a spacer on the axle that is a part of the axle. I thought that was the only spacer; and after looking at the inner bearing on both wheels I didn't see another spacer to transfer over to the new wheel.After installing the wheel; it torqued up correctly and had what appeared to be the correct amount of threads remaining past the axle nut. We then performed a 'wiggle' check; with no wiggle present. When we started to change the nose tire the departure time was XE:00am. About the time we started to jack the aircraft; the departure time was changed to XD:00am [one hour earlier] without any notification. To prevent a delay we hurried. We completed the task before XD:00am. The actual departure time didn't change; it was XE:00am despite our efforts. Preventive measures; [would be] physically running my fingers over the removed tire's inner bearing surface to feel if there was a thin spacer stuck to it. Not worrying about getting a delay.
More incidents for this aircraft family →
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.