Date: 202111
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Light: Daylight
Aircraft: Any Unknown or Unlisted Aircraft Manufacturer
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Parked
ATC / advisory: Ramp ZZZ
Aircraft component: AC Generator/Alternator
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Technician
Reporter qualification: Maintenance Powerplant; Maintenance Airframe
Human factors: Troubleshooting; Situational Awareness; Human-Machine Interface; Communication Breakdown
Second reporter function: Technician
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural FAR
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Returned To Departure Airport; Flight Crew Landed in Emergency Condition; General Flight Cancelled / Delayed; General Maintenance Action
Contributing factors: Aircraft; Human Factors; MEL; Procedure
Primary problem: Procedure

Narrative: Aircraft X came in with a write up for the #1 Integrated Drive Generator system (IDG) erratic temperature fluctuations. NAME was sent out to the aircraft. When he got to the aircraft he pulled the post flight report and noticed that the APU generator had also had a failure during the last flight leg. Having two faulty generators prevented the MEL from being able to be applied. My recommendation to the management was to change the #1 IDG because of the history; parts previously changed; and the post flight flagging. My supervisor NAME1 was told by his boss that the hangar was too busy to accommodate and pressured him to troubleshoot the APU further. An avionics tech who was previously on the aircraft was sent out to troubleshoot the A/C. Parts had been ordered to troubleshoot the issue with the APU; and the IDG. NAME3 was the avionics tech assigned. He performed an ops-check of the generator that was good. And as a precaution changed the GAPCU (Ground and Auxiliary Power Control Unit). It was expressed multiple times that this aircraft really needed an IDG; and APU generator. The #2 IDG did require servicing as well. I believe this aircraft was handled the way it was because of pressure from management to get the aircraft out. I did some research on the history of the rest of the aircraft later that day [and] found that the aircraft had had prior issues with the batteries and the RAT (Ram Air Turbine). With the history of electrical generation issues on this aircraft I believe this was a near miss. The aircraft was dispatched with a #1 IDG on MEL and an unconfirmed repair to the APU; leaving the aircraft with one operable generator; that needed servicing. The emergency electrical generation issues with the battery and the RAT are even more reason for concern. The result of this event was [a priority] landing. The aircraft was routed to go to ZZZZ and on climb out lost the APU generator. The aircraft then returned to field. Flight time was approximately 30 minutes. I was informed that it was [a priority] landing by my supervisor NAME1. To my knowledge there was never any maintenance log write up for [a priority] landing or an overweight landing. The next day I spoke with the Chief pilot notifying him of the incident. I was called up to the manager's office later that day. NAME2 berated me for going to the chief pilot before contacting him for this issue. I explained to NAME2 that I was not trying to hide anything from him. That day I didn't have the time to come in early and speak to him about this issue. The chief pilot's office happens to be less than 100 feet from where my overtime shift was that morning. I explained to NAME2 why I felt this was unethical to allow the aircraft to fly in this condition. NAME2 became irate that I said 'I felt this was unethical'. He said not to use the word 'unethical' when it came to this repair as the [manual] said it was good. I explained that having repaired the APU generator with an 'ops check' is not a confirmed repair and having sent it out with a #1 IDG on MEL was dangerous. That is all in addition to the previous history of electrical problems this aircraft had prior.This is just another example of how the company tries to use the maintenance manuals and company manuals to cut corners in maintenance. Common sense and general safety would say not to dispatch the aircraft without a confirmed repair to one of the two generators. This behavior seems to be more and more common in a place where the punitive management culture pushes its front-line supervision for on time departure over safety.


Second narrative: I was called out to the aircraft with NAME because of a pilot discrepancy about E1 IDG erratic temperature. I helped him check the E1 IDG oil level and found it to be in the green range. When he said he was going to put it on MEL I went to the number 2 engine and checked the IDG oil and found it to be at the top of the lower red band so I proceeded to service that IDG oil to insure its proper operation. The aircraft was at the gate when I worked on it. I assumed that the checking and servicing procedure for the opposite engine was part of the MEL and that's why I didn't document it.I didn't realize that there was a problem until I was questioned about not documenting the IDG oil servicing because I thought it was in the MEL and didn't need to be.Return the procedure of checking the opposite engine IDG and the APU oil to the MEL procedures.


Synopsis: Technician reported the APU failed in flight as a result of incorrect trouble shooting procedures. The #1 IDG was already on MEL; causing single generator operation.