Technicians reported an aircraft slipped off the axle jack during main wheel replacement; damaging a vehicle.
Synopsis
Technicians reported an aircraft slipped off the axle jack during main wheel replacement; damaging a vehicle.
Narrative
On Date; I was assigned to work on Aircraft X. The aircraft was out of service due to hydraulic contamination issues. I was assigned with Mechanic to a transit inspection check. While doing the exterior inspection of the tires I found the #2 and #4 tires worn. The #2 MLG tire was replaced without incident. Using the same 95 ton jack; with the #4 MLG tire removed and the new tire secured on the axle. I entered the flight deck to release the parking breaks to allow the rotation of the tire to facilitate the torquing of the nut; to complete the installation. I released the brakes and heard and felt a loud noise from the aircraft. I reset the brakes to secure the aircraft. Upon further evaluation the axle jack was ejected from the right MLG strut. The jack struck the service cart parked approximately 12 ft. forward of the gear. I noticed hydraulic fluid on the floor under the jack as well as the underside of the axle. It appeared that the jack had failed. None of the others assigned were hurt as other maintenance was being performed. Name and I went to retrieve another jack to complete the torquing of the #4 tire and accomplish a more detailed inspection of the underside of the Right MLG. An initial inspection found damage to a bracket for electrical conduits as well as the forward edge of the truck.
Second reporter narrative
On Date; Name 1 and I where tasked with a 'T' check to be accomplished on Aircraft X. Multiple maintenance jobs were being performed at that time. Name 1 noticed the #2 as well as #4 tires were below limits. Name 1 proceeded to document his findings in the log book and print the required maintenance documentation. As I started the procedure of gathering ground equipment and installing the aircraft's gear pins for essential maintenance. Furthermore; using a 95 ton jack we successfully removed and replaced the #2 tire with no incident. Subsequently; we moved on to #4. As I did with the #2 tire; so I did with the #4. Ran the 95 ton jack adjustable threads to approximately one inch short of the mating service on the aircraft. Moreover; as nitrogen began to elevate the plane; I visually verified the mating surfaces were aligned. Continuing with maintenance procedures we removed the tire and installed the new one. As my colleague released the brakes to apply the required torques; while in addition my back was to the aircraft; as I was cleaned the grease gun used for installation. There was what sounded like a shotgun blast. There upon I turned around; and moments later there was a spark as the jack was ejected from the aircraft. Thereafter upon investigation; aircraft damage was found.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.