Technicians reported communication and coordination problems led to not installing a brake axle spacer when replacing a main wheel tire assembly. The tire and wheel assembly failed catastrophically in service.
Synopsis
Technicians reported communication and coordination problems led to not installing a brake axle spacer when replacing a main wheel tire assembly. The tire and wheel assembly failed catastrophically in service.
Narrative
I was tasked; along with a team of 4 total; to complete a reasonable amount of work on Aircraft X a Boeing 767 Aircraft. We got our work around XA30 as we usually did and the 4 of us grouped together to plan out who was to be working as a team and on what tasks. Person A and I were a pair and Person B and Person C were the other pair. Person A and I had worked on the number one engine that evening as our main tasks. Throughout the night other than brief interactions the two teams did not interact too much. More towards the later hours of the morning; Person A and I had come to the conclusion of our work. During our final clean up and second checks it came to my attention that; due to a leak in the number one tire; the other team wanted to change the tire. I offered my helping hand to have the job go smoother; because I was available and did not want to simply abandon these guys in the cold alone while i returned to the office to rest while they worked. Firstly; everyone set off quickly to acquire all the different tools and parts that are needed to do the change. I believe I was in the bathroom when everyone broke and so proceeded to run back to the office where the tires are kept to aid in its acquisition given how heavy they are. I helped Person B get the tire from the container and rolled it over onto the tire jack cart which Person C had already positioned and connected to the truck. I got in the vehicle with him and we drove back over to the plane. Once we got there I exited and dropped the ramp to roll the wheel off of the cart. Person C and I rolled it together over to the gear and leaned it up on the number two tire so it would be out of the way; he then proceeded to disconnect the cart; move it together over to the gear and position the jack; Person B worked the tanks while I worked the jack and in little time we had the plane jacked up and ready to go. I then stepped away to start signing off and reviewing the work that I had done earlier that evening. When I returned to the tire job; since I already had my iPad out; I offered to write up the tire discrepancy for Person B after asking if they had done so already. I wrote it up for them and then proceeded to fill out the component replacement paperwork for them since it is a bit of a hassle. By the time I was done with that they were ready to take the old tire off and so I wheeled over the tire raiser cart jack piece of equipment and positioned it under the tire. I then stood by passing time and awaited their go ahead to jack it up to cradle the tire. They removed the tire while I moved the cradle back off the axle. Once I cleared it was safe I dropped the cradle down to get the tire on the ground. I rolled the tire away over and leaned it up against the truck. I do not remember If I aided in rolling or positioning the new tire over but I did man the wheel cradle jack again. I forgot who but someone positioned the new wheel onto the cradle jack and when everyone was ready I jacked it up and positioned the tire and worked with them to get the proper height on the jack so that the tire would go onto the axle. Once I saw that it was on; I lowered the jack; moved it out of the way and got myself out of the way so that they could work. At this time; I stepped away to the old tire for a bit to see and watch Person C deflate the old tire and to briefly banter with him while we waited. Sometime later I noticed that Person B was having a hard time with the tire and I commented that I did not believe it was seated all the way or properly on the axle. When it was decided; by them; they wanted to take the tire all the way off and try again; I got the tire cradle jack again and positioned it just as I had done previously; I got the cradle up; We took the tire off and I got it out of the way while they investigated the axle. I noticed that they found the old tire's bearing still in and on the axle. I briefly took note of them removing it; but did not really pay attention to it.My attention was on my phone while I was waiting for them to say they were ready to put the new tire back on. When they said they were ready; I positioned the new tire just as I had done before and aided them in getting it back on the axle. My next steps mirrored exactly what I had done previously. I lowered the cradle and got it out of the way and then stepped aside myself. From this point forward I was more of a floater just hanging out until the job was done or helping clean the odd thing here or there. At one point I did assist with holding the torque wrench in place as they had made a commotion about it not working properly or having a hard time with it. I held it in place briefly. It seemed to work fine and then I stepped away again to help clean up dirty rags around until everything was done with. At the very end I did help Person B put the cap back on the tire as it's a pain to do alone to fish that bolt back through the other cap. Afterwards; I went with Person C to return the torque wrench and tire change kit. When we got back to the office I proceeded to go about my own business.I was shocked and mortified to find out a couple days later when I was informed that the tire had experienced a rather catastrophic failure. Over the past few days it has come to my attention that a spacer was left out on the inner portion of the axle. My heart dropped as I remembered the issue Person B had had getting the tire on and that they had removed the old bearing. I immediately came to the conclusion that the spacer must have accidentally been removed as well and put to the side. I never really saw the bearing after the brief moment they took it out and thought nothing of it at the time. My experience with the 767 tire change is limited having only really done it maybe once before this. I was unaware of the fact that that spacer even existed. I came to find out later that it is mentioned specifically in the manual. I assumed that the manual had been used as you need it to get the torque values. Since I was only helping in a supportive logistical role I did not have the reference open myself and just tried to stay out of the way when I was not needed.
Second reporter narrative
Task - remove and replace number 1 Tire and Wheel assembly. 767-300. Aircraft X. The proper tooling and MLG (Main Landing Gear) tire change kit were acquired. During the service check; that particular tire pressure was low. Upon further troubleshooting the valve stem was determined to be leaking. The valve stem was tightened into the wheel bringing the air leak to almost a complete stop. A leak check was preformed to determine this. Against my judgement it was determined by one tech out of four that he wanted to remove and replace the tire. While working the remove and replace task some difficulty was encountered trying to install the tire on the axle. The tire and wheel assembly would not slide completely on the axle. Upon further investigation; it was discovered that the original inner wheel bearing and seal remained on the axle. When the original wheel bearing and seal were removed the inner wheel spacer obviously went with it unnoticed. This assembly of parts was placed on top of the old wheel and tire assembly for further inspection. After inspecting the new wheel and tire assembly for the inner wheel bearing and determining it was complete; then returning to the old tire wheel assembly only to find the old bearings were reinstalled in the old tire and capped up by another technician. So then going back to the new tire wheel assembly we then continued on with the assembling of the new tire; wheel and it slid on the axle all the way properly. After referencing the AMM for torque value; the axle nut was installed and torqued with the proper tooling. Proper torquing took two attempts because of the special tooling required reset twice. The preload and proper torque was achieved and the gland nut locking bolts were installed. Required amount of threads looked correct. Two. This having been my first 767 MLG tire replacement I felt confident all was in order. I also felt pressure that all tasks must be done in a timely manner and should not take triple time.
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Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.