Summary
We propose to supersede airworthiness directive (AD) 2013-15- 03 for Eurocopter France Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350C, AS350D, and AS350D1 helicopters with a single hydraulic system and a certain hydraulic pump drive assembly installed. AD 2013-15-03 requires inspecting the hydraulic pump drive bearing (bearing) for leaks, rust, overheating, and condition. This proposed AD would add a requirement to grease the bearing and inspect for bronze particles in the grease, as well as change the inspection and inspection intervals of the bearing until it is replaced with an improved bearing. These proposed actions are intended to prevent hydraulic pump drive belt failure, loss of hydraulic servo assistance, and subsequent loss of helicopter control.