B757-200
Maintenance Powerplant; Maintenance Airframe
Communication Breakdown; Situational Awareness; Troubleshooting
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
Human Factors; Aircraft
A B757-200 aircraft had the Fuel Flow Governer changed previously for slow/no start condition on Engine Number 2. Removal and Replacement (R/R) was accomplished IAW Aircraft Maintenance Manual (AMM) 73-21-01-XX; and the Jet Run-up Handbook (JRH). Five [different] Engine tests were performed [including Test X] and the item FACT'ed [Cleared]. The engine still did not start reliably after return from engine run and further troubleshooting was conducted by next shifts. The last test performed was Test X; [for the] Acceleration/Deceleration Test. This Test goes past the point of the Part Power Stop (PPS); which would not have been possible had the stop been engaged. This was confirmed by ground personnel and RII. The Part Power Stop is in a location that lends readily as a handhold rather than [compared to] cables or plumbing. It is very likely that during the following maintenance troubleshooting and repair the stop was inadvertently engaged. There is no positive lockout mechanism. [Recommend] some type of safety could be installed to prevent inadvertent engagement of the Part Power Stop. Equipment malfunction.
A Line Aircraft Maintenance Technician (AMT) reports about a Part Power Stop (PPS) that was inadvertently engaged on a B757-200 aircraft engine after a Fuel Flow Governor replacement. Technician also noted the lack of a positive lockout mechanism to properly secure the PPS.