B777 Undifferentiated or Other Model
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown
Aircraft Aircraft Damaged
Human Factors; Procedure
We had just finished replacing the Thrust Reverser Blocker Doors on the #2 engine of Aircraft X which we had been working on for a couple of days. The only fully qualified mechanics on duty were myself and [another technician]. As [the other technician] was unable to climb the thrust reverser fan duct in order to access the upper blocker doors the inspection and sign off of those doors fell to me. I had climbed up the fan duct of the thrust reverser several times over the previous and current shift. As the job was finished and we were preparing for ops checks I climbed into the fan duct to conduct a final inspection of the installation and to make sure no tools or FOD had been left behind. During my final inspection of the left hand side my foot slipped off the hinge fitting I was using as a foot hold and I slid down the fan duct. My foot landed on the wedge fairing but due to its sloped shape I slipped to the forward side landing my weight on the very tip of the fairing breaking it off. Confined space; lack of maneuvering room; and lack of secure foot or hand holds contributed to the incident. As I am a large individual I had to contort my body in the very forward portion of the duct just behind the blocker doors. This afforded me just enough room to bend my legs to climb up the duct using the hinge fittings and the aft side of the wedge fairings to support myself. When the blocker doors are removed there are places to use as hand holds but with the doors installed there are no secure hand holds. Per the [maintenance manual] there is an access platform system of foam blocks designed to be used in the thrust reverser fan duct to prevent falls or damage to the aircraft. However due to my size and the lack of space I am not sure I would fit in that location if any additional equipment was installed with me. Also performing the door adjustment requires the access platform to be removed. Based on the [maintenance manual] description of the platform I believe it could be used but only you are able to remove sections so you could adjust the height. If the tool has to be installed as a whole assembly it would not be effective for this task due to having to remove it to perform the door rig.
Maintenance Supervisor reported that the tip of a fairing on a Boeing 777 fan reverser was broken off during maintenance.