Date: 202004
Local time of day: 0001-0600
Flight conditions: VMC
Light: Night
Aircraft: B767-300 and 300 ER
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Cargo / Freight / Delivery
Flight phase: Parked
Aircraft component: APU Fuel System
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: Technician
Reporter qualification: Maintenance Powerplant; Maintenance Airframe
Human factors: Communication Breakdown
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Maintenance
When detected: Aircraft In Service At Gate
Result: General Flight Cancelled / Delayed; General Maintenance Action
Contributing factors: Aircraft; Human Factors; MEL; Procedure
Primary problem: Procedure

Narrative: Per Tech Service request; replaced APU Fuel control unit on [date]; for deferral. FCU was no help; APU would not start; and no fuel supply was discovered at FCU. Thus; I could not complete a leak and ops check. I notified my Supervisor and then contacted [Maintenance Control]. I explained the situation to the 767 Controller; and suggested we open a deferral against the FCU leak and operational check. [Controller] informed me that he was not authorized to issue a DMI against an already existing open deferral. He suggested I just note the open leak and ops check in the maintenance comments attached to the APU deferral. I raised my concerns/objection to this course of action primarily due to the fact that there would be no real visibility or accountability. The potential to miss a critical step seemed to be glaringly obvious. I again stated my objection; to include the possibility of taking the airplane out of service. [Controller] suggested conferencing in with Engineering to investigate any EO relief. The powerplant engineer seemed not to grasp the intent; and indicated that this is not something he could or would be inclined to provide relief for. At that point; I turned the issue over to Maintenance Supervisor. After consulting with Manager; [Supervisor] came back to me; explained that there was simply no relief for adding additional deferral; and that he had assurances that the item would be tracked; and accomplished at the first opportunity; and that again; simply adding maintenance comments to the open deferral would suffice. After again raising my objection to this course of action; I was 'directed' to document the FCU removal and replacement; and to progress the deferral with maintenance comments indicating FCU leak and ops check needed to be accomplished. And so; working as 'directed'; I entered the pertinent information. The need to accomplish Leak and ops was stated directly and clearly to include Paragraph/step/subtasks required. On the Morning of [date]; I was informed by a coworker that [Maintenance Control] had been trying to contact me on the evening of [date] with regard to Aircraft X APU. Apparently; The APU deferral had been cleared in ZZZ on [date] by replacing the ECU (electronic control unit). No mention whatsoever with regard to FCU leak and ops check. Maintenance Supervisor who was on duty that evening noticed this maintenance activity; and called [Maintenance Control] to confirm that the Leak and ops had been addressed. Not surprisingly; no one in [Maintenance Control] was aware. Luckily; Aircraft X was called out of service until the item could be accomplished before flight. The item was opened as an M item on logpage as 'per [Maintenance Control] finding reference logpage apu fcu requires leak and ops check; and subsequently cleared as C/W.




Synopsis: Technician reported that operational and leak checks were not accomplished after component replacement because of failure to track required checks in the MEL procedures.