B767-300 and 300 ER
Maintenance Airframe; Maintenance Powerplant
Communication Breakdown; Training / Qualification
Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown
General Maintenance Action
Company Policy; Procedure; Manuals; Human Factors
Aircraft X arrived with an ELB (Electronic Logbook) report regarding the left engine hydraulic pressure. The corrective action required engine operation to test the hydraulic pump. After setting up the cockpit in accordance with the maintenance manual and receiving clearance from the techs on the ground I was in the process of motoring the left engine when someone barged into the flight deck from behind me; reached over my head; operated some switches on the overhead panel; exited the plane and drove away from the aircraft. After he left I realized he had turned off the main battery causing the APU to shut down aborting the engine motor procedure. I realized the person who interfered was an [outside] vendor and summoned him back to the aircraft. When he returned he told me that he turned the battery off because he was told to 'return the cockpit to the way he found it'. He did not follow any checklist and had no idea what happens when the battery is turned off and seemed to be unfamiliar with the cockpit. He was oblivious to the severity of what he had done and seemed to be unaware of his surroundings regarding the maintenance operation being performed. It was obvious that he should have recognized the maintenance operation being performed at the time of his interference.It would be disturbing to me to find that the company allows inexperienced; untrained and unqualified vendors to operate systems in the flight deck on [company] aircraft. Besides the obvious safety concerns this also may be a security threat.
Air carrier maintenance technician reported an outside vendor entered the flight deck and reconfigured the aircraft systems without communicating to maintenance; causing the maintenance procedure to be aborted.