Challenger 350
Maintenance Airframe; Maintenance Powerplant
Communication Breakdown; Situational Awareness; Training / Qualification
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Aircraft; Human Factors; MEL; Procedure
On Date Aircraft X [Company] Rev 00 deferral per MEL 25-XX-XX was put in place for the two forward life-rafts removed (due overhaul) while parked at ZZZ; the 3rd life raft remained installed. Due to the remote location of the aircraft vs home base; the flight crews physically performed the life raft removal and transport to the service facility absent of direct maintenance personnel; acting as the Maintenance Director designee as requested; instead of talking the crew through performing the deferral per our operations manual I performed the electronic paperwork side of the process without verifying that an INOP placard was applied to the empty cabinets by the crew. The lack of proper [Company] MEL placarding wasn't discovered until after an event revealed the lack of placarding several weeks later after Aircraft X flew more than 50 miles from shore.Recommend adding routine discrepancy/MEL training for all [Company] personnel to build comfort with deferral writing and operating manual procedures in place; in this case; specifically as it applies to responsibilities for corrective/deferred actions. We could also emphasize how important it is for flight crews to monitor the deferral list prior to every departure and be free to ask questions about discrepancy questions to our Maintenance Director. I will also ask for a picture of the in place placard for the next deferral opportunity.
Challenger 350 Technician reported that MEL placards were not installed after life rafts were removed for overhaul.