Airbus Helicopters developed, within the 2018 top irritant program, a new solution to reduce the maintenance burden on the Main Rotor Blade vibration absorber for the H145 aircraft:

• To switch the lubricating oil type in the vibration absorbers from MIL-PRF-23699 (CM 103) to ZNF-L-3001(CM 1001). The oil change requires approximately 2 hours per blade for a dynamic mechanic.
• To install new designed shaft seals (inner shaft seal P/N B621M30X1205 and outer shaft seal P/N B621M30X1206). The seals change requires approximately 3 hours per blade.
• Operators will benefit from reduced mechanical parts’ wear and enhanced protection from leak tightness.

This solution is available for BK117 C-2 and D2 through Service Bulletins (SB MBB‐BK117 C‐2‐62‐015 and SB MBB‐BK117 D‐2‐62‐010). All products are mixable, the former oil can be used with the new shaft seals and the new oil can be used with the old shaft seals.