Maintenance Powerplant; Maintenance Airframe
Situational Awareness; Troubleshooting; Communication Breakdown; Distraction
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural FAR
Flight Crew Returned To Gate; General Maintenance Action
Aircraft; Procedure; MEL; Chart Or Publication; Human Factors; Incorrect / Not Installed / Unavailable Part; Logbook Entry
I troubleshot a #2 engine anti-ice valve discrepancy on an A320 aircraft. I reactivated the valve for troubleshooting and determined that there was good voltage to the valve. I manually actuated the valve and noticed a sticking in the 'Closed' position and determined the valve was bad. We did not have a valve in stock so I was told to defer the discrepancy. I mistakenly deactivated the valve according to MEL 30-27-01A instead of MEL 30-27-01D. At this point in time I do not know how I made this error. My only thought is that due to poor lighting in the cockpit I mistook the 'D' for an 'A'. Aircrew noticed improper anti-ice valve indication on engine start. I did not thoroughly review which MEL had been applied to the aircraft. Proper MEL was applied [after a] gate turnback. Suggest [I] thoroughly review and make sure I understand which MEL has been applied to the aircraft.
A Line Mechanic reports he mistakenly deactivated #2 engine anti-ice valve according to MEL 30-27-01A; instead of MEL 30-27-01A. Flight crew returned the A320 aircraft to gate after noticing improper anti-ice valve indication during engine start.