Date: 202104
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: A319
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Parked
Airspace: Class B ZZZ
Aircraft component: Oil Storage
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Technician
Reporter qualification: Maintenance Powerplant; Maintenance Airframe
Human factors: Workload; Communication Breakdown; Situational Awareness; Time Pressure
Second reporter function: Technician
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Maintenance
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Inflight Shutdown; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Took Evasive Action; Flight Crew Landed in Emergency Condition; General Flight Cancelled / Delayed; General Maintenance Action
Contributing factors: Aircraft; Equipment / Tooling; Manuals; Procedure
Primary problem: Procedure

Narrative: My partner and I were assigned to install the IDG on Aircraft X; from the turnover on midnight shift. We proceeded to Bay 2; and attempted to install; and had some difficulties getting the IDG to mount to the gearbox. We had a crew chief come out and assist us with the installation; and after a bit; we moved the quad ring and got the IDG to mount. We then completed the installation; pushed the aircraft; and ran the engine twice. The first run was to verify the disconnect of the IDG worked; and the second time was to verify it was reset properly. There was a crew chief and another 2 AMT's doing the leak check; and no leaks were noted. The cowlings were closed; and we then taxied the aircraft to the gate. We did a post taxi walkaround; and saw no leaks and or fluid coming out of the engine. We were notified of engine oil loss during flight from the gearbox pad cover not being installed. At no time did we notice the pad cover off; nor were we told it was removed during the installation.


Second narrative: My partner and I were assigned to install the IDG on Aircraft X; from the turnover on midnight shift. We proceeded to Bay 2; and attempted to install; and had some difficulties getting the IDG to mount to the gearbox. We had a crew chief come out and assist us with the installation; and after a bit; we moved the quad ring and got the IDG to mount. We then completed the installation; pushed the aircraft; and ran the engine twice. The first run was to verify the disconnect of the IDG worked; and the second time was to verify it was reset properly. There was a crew chief and another 2 AMT's doing the leak check; and no leaks were noted. The cowlings were closed; and we then taxied the aircraft to the gate. We did a post taxi walkaround; and saw no leaks and or fluid coming out of the engine. We were notified of engine oil loss during flight from the gearbox pad cover not being installed. At no time did we notice the pad cover off; nor were we told it was removed during the installation.


Synopsis: Technicians reported leaving the accessory gearbox drive pad cover uninstalled and released the A319 aircraft for service.