EMB ERJ 170/175 ER/LR
Maintenance Powerplant; Maintenance Airframe
Training / Qualification; Workload; Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
General Flight Cancelled / Delayed; General Maintenance Action
Incorrect / Not Installed / Unavailable Part; Human Factors; Chart Or Publication; Aircraft; Manuals; Procedure
On the date of DATE me and another tech changed the high stage valve instead of the Nacelle pressure shut of valve; when opening up the engine we mistake the high stage valve for the shut off valve due to the fact that they are identical and close to each; we used the ipc to confirm the correct part number; but we was looking at the high stage valve. we used the wrong ref AMM 36-11-03 to change the high stage valve which we mistaken for the and nacelle shut off valve.In the AMM ref put a detailed step stating that there are two of the same valves that is right next to each other that is the same part number.
During maintence on Aircraft X; request from Maintenance Control; removed and replaced nacelle pressure shut of valve from log page. I replaced the high stage bleed valve instead of the nacelle pressure shut off valve. Both valves are identical in part number and are located side by side on the engine. Its very easy to confuse one from another. I suggest this could of been prevented if we had markings or decals on the engine that would have clearly indicate one valve from another. Another mechanic and supervisor assisted with maintenance and were also confused as the AMM Refernces pages; and pictures look very identical and refernces are one after another in the AMM.
Technician reported unclear references in the Aircraft Maintenance Manual resulted in replacing the wrong valve on an aircraft engine.