A320
Maintenance Airframe; Maintenance Powerplant
Distraction; Training / Qualification; Situational Awareness; Confusion
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Aircraft; Chart Or Publication; Human Factors; Incorrect / Not Installed / Unavailable Part; Manuals
I was assigned to work an MEL on an A320 aircraft and I was supposed to change the High Pressure (HP) 10th stage bleed valve closure solenoid (4029ks). Instead I changed the HP 10th stage solenoid (4023ks); not realizing I changed the wrong solenoid because the terminology confused me. See Aircraft Maintenance Manual (AMM) figures [drawings] in Chapters 75-23-53 and Troubleshooting Manual (TSM) 36-11-00. I was working at night; outside on Pad-5 on my third night. At the same time; I was assisting a Mechanic working a 2.5 bleed actuator on the opposite motor and may have been distracted. I had changed the wrong part and re-deferred the MEL. Two nights later; another Mechanic was assigned the same job to fix the MEL; but could not locate the part in stock that I had installed incorrectly. After researching; that Mechanic found the part installed in the incorrect position. Distraction and confusion between AMM figures in 75-32-53 and TSM 36-11-00; the MEL was cleared during the second visit.
An Aircraft Maintenance Technician (AMT) reports he mistakenly changed the High Pressure 10th stage solenoid (4013ks) instead of the High Pressure (HP) 10th stage bleed valve closure solenoid (4029ks) on an A320 aircraft engine. Distraction with helping another Mechanic and confusion with the drawings in the Aircraft Maintenance Manual (AMM) and Troubleshooting Manual (TSM) were noted as contributors.