Maintenance Airframe; Maintenance Powerplant
Confusion; Situational Awareness; Communication Breakdown
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Aircraft; Incorrect / Not Installed / Unavailable Part; Chart Or Publication; Human Factors
[Pratt-Whitney PW-120A] Engine Serial Number (S/N) XXXX-48 was involved in a over-torque on a DHC-8-100 aircraft; at Number 1 position. Engine was changed and sent to Engine Shop. I was instructed by Engine Program Manager to remove Engine S/N XXXX-48's Reduction Gearbox (RGB) (S/N XXXX-06) and install RGB S/N XXXX-24 to make Engine XXXX-48 Serviceable again. Task was completed and engine was signed in Serviceable; February 2014. Engine S/N XXXX-48 was then installed on another DHC-8-100 aircraft; at Number 1 position. Two days later; I was told by the Engine Program Manager that Engine S/N XXXX-48 needed to go out for overhaul. I told him that engine was already installed and flying. I showed him the paper he gave me with his workscope of that engine. After much headshaking he admitted his mistake and thought we did the gearbox swap on Engine S/N XXXX-26. That Engine is in the Shop minus the gearbox. I confirmed with him many times during the repair of Engine S/N XXXX-48; reference to his workscope; that we were doing the correct thing. [The second DHC-8-100] arrived in ZZZ later in the afternoon with torque problems. Questioned Manager's decision to send an engine out for overhaul. Followed Manager's plan. Engine on Aircraft Y was changed. Double check Manager's decision.
A Lead Aircraft Maintenance Technician (AMT) explains how an apparent lack of adequate communication between himself and their Engine Program Manager led to the removal of an overtorqued Engine from one DHC-8-100 aircraft and installed on another DHC-8 aircraft that later arrived with the same torque problems. Engine had been scheduled for overhaul; not installation.