Narrative:

While performing lock-out procedures to 'install elevator power control actuator lock tool' per aircraft maintenance manual (amm) 27-31-05-022-001; I misunderstood the procedures as they were poorly written. I installed the lock tool on the [power control] actuator (positive control area) with hydraulics 'on' and elevator full 'up'. When I told my partner on the flight deck to slowly lower the elevator; the lock tool was damaged. I immediately told my partner to stop and hold the elevator back; [to] full 'up'. I removed the damaged lock tool and inspected the positive control area for damage. No damage was found. Realizing I was doing something wrong; I called my supervisor and asked for assistance. He sent out a lead technician who agreed with me that the procedures were poorly written. He assisted me in correctly installing another lock tool. The lead submitted a publication change request to improve the procedures and safety. The broken lock was reported to the tool room and the plane flew two days later without incident. There is an unfortunate mindset among mechanics that they should know how to do every job; even ones they have never done before; without asking for help. This particular supervisor belittled me when I asked him to send someone out to help. 'You need help installing a lock on an actuator?' were his exact words. I didn't care and I'm glad I did; as it avoided costly damage to the aircraft. Lack of experience in task.

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Original NASA ASRS Text

Title: A Mechanic and a Lead Mechanic describe various factors that contributed to an Elevator Power Control Actuator lock-out tool being installed incorrectly on a B767 aircraft.

Narrative: While performing lock-out procedures to 'Install Elevator Power Control Actuator Lock Tool' per Aircraft Maintenance Manual (AMM) 27-31-05-022-001; I misunderstood the procedures as they were poorly written. I installed the lock tool on the [Power Control] Actuator (PCA) with hydraulics 'On' and elevator full 'Up'. When I told my Partner on the flight deck to slowly lower the elevator; the lock tool was damaged. I immediately told my Partner to stop and hold the elevator back; [to] full 'Up'. I removed the damaged lock tool and inspected the PCA for damage. No damage was found. Realizing I was doing something wrong; I called my Supervisor and asked for assistance. He sent out a Lead Technician who agreed with me that the procedures were poorly written. He assisted me in correctly installing another lock tool. The Lead submitted a publication change request to improve the procedures and safety. The broken lock was reported to the Tool Room and the plane flew two days later without incident. There is an unfortunate mindset among mechanics that they should know how to do every job; even ones they have never done before; without asking for help. This particular Supervisor belittled me when I asked him to send someone out to help. 'You need help installing a lock on an actuator?' were his exact words. I didn't care and I'm glad I did; as it avoided costly damage to the aircraft. Lack of experience in task.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.