EASA 2019-0169

Supersedes but retains the requirement of EASA AD 2019-0003, which requires an inspection of the main rotor mast bearing lubrication system for foreign objects, and adds a one-time inspection of the mast bearing lubrication line and, depending on findings, the accomplishment of applicable corrective action(s). Prompted by “uneventful occurrences” of foreign object debris (FOD) generated during the manufacturing and/or overhaul of main gearbox assemblies. Results of an EASA technical investigation identified that FOD in the main gearbox might lead to a loss of lubrication of the mast bearing.