What happened
On November 29, 2017, a crew based at the Płock branch received a mission to attend an accident in Pawlik. During the engine start sequence of the EC 135 P2+, the crew observed several warnings and notifications on the Crew Alert Display (CAD), specifically the XMSN CHIP alert, indicating the presence of metal chips in the main gearbox.
Following the detection, the pilot shut down the engines and reported the incident to the Technical Coordination Center. The aircraft was immediately removed from service for inspection.
The investigation
Maintenance personnel from the Warsaw-Babice Maintenance Station conducted an inspection of the main gearbox chip detection system in accordance with the manufacturer's technical instructions (SB63A-012 rev.6). During this inspection, technicians identified a