Narrative:

While troubleshooting inbound write-up; we were advised to defer item by maintenance control per MEL/amm (aircraft maintenance manual) and proceeded to 'lock-out' the high pressure (hp) valve. After opening the left inboard cowl; we then locked-out the hp valve per the maintenance manual and MEL procedures. There were two supervisors and two mechanics; as well as myself; observing the operation. My position while observing the procedure was from behind mechanic Y; who was doing the valve lock-out. The position of the valve was the most aft of the engine. I could not see the pressure regulating valve (prv) from my vantage point. All of us agreed and confirmed the lockout procedure and visually checked the valve to make sure of the proper valve position via the position indicator as well as the correct valve was locked-out; verified by maintenance manual task 36-11-00-040.if the incorrect valve had been locked-out; there would have been no air from the #2 engine and no bleed air indication on the ECAM air page. The aircraft would have [had] to taxi back to the gate; as well as [had] an ECAM warning message.a hard copy was printed of the aircraft condition monitoring system (acms) real time cruise performance report from the date; time; and flight after valve lockout. The correct valve position; status; and operation was confirmed in the description of parameter page in the amm.maintenance control notified that the incorrect valve had been locked-out. There is no possible way the incorrect valve had been locked-out by ZZZ maintenance. There was no maintenance performed on the prv by ZZZ station that night; only the hp valve. [This was the] other station's troubleshooting problem.

Google
 

Original NASA ASRS Text

Title: Three Line Mechanics and two Line Maintenance supervisors report about the troubleshooting; locking-out; and deferral of the High Pressure Valve (HPV) on #2 engine of an A330 aircraft. Downline Maintenance Station had reported the wrong valve was locked-out. Questions were raised whether Downline Maintenance had used a Pratt & Whitney manual instead of Rolls Royce Trent 770 engine manual.

Narrative: While troubleshooting inbound write-up; we were advised to defer item by Maintenance Control per MEL/AMM (Aircraft Maintenance Manual) and proceeded to 'lock-out' the high pressure (HP) valve. After opening the left inboard cowl; we then locked-out the HP valve per the maintenance manual and MEL procedures. There were two supervisors and two mechanics; as well as myself; observing the operation. My position while observing the procedure was from behind Mechanic Y; who was doing the valve lock-out. The position of the valve was the most aft of the engine. I could not see the pressure regulating valve (PRV) from my vantage point. All of us agreed and confirmed the lockout procedure and visually checked the valve to make sure of the proper valve position via the position indicator as well as the correct valve was locked-out; verified by maintenance manual task 36-11-00-040.If the incorrect valve had been locked-out; there would have been no air from the #2 engine and no bleed air indication on the ECAM air page. The aircraft would have [had] to taxi back to the gate; as well as [had] an ECAM warning message.A hard copy was printed of the Aircraft Condition Monitoring System (ACMS) real time cruise performance report from the date; time; and flight after valve lockout. The correct valve position; status; and operation was confirmed in the Description of Parameter page in the AMM.Maintenance Control notified that the incorrect valve had been locked-out. There is no possible way the incorrect valve had been locked-out by ZZZ Maintenance. There was no maintenance performed on the PRV by ZZZ station that night; only the HP valve. [This was the] other station's troubleshooting problem.

Data retrieved from NASA's ASRS site as of April 2012 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.