Summary
This action withdraws a notice of proposed rulemaking (NPRM) that proposed a new airworthiness directive (AD), applicable to Sikorsky Aircraft Model S-76B helicopters. That action would have limited the applicability of the inspections of the left and right engine input drive shaft assemblies (shaft assemblies) for loose balance weights or cracks to those shaft assemblies of original (or initial) design only, and would have excluded redesigned shaft assemblies from those inspections. Since the issuance of the NPRM, the FAA has received a report of a fatigue crack in a redesigned shaft assembly indicating a need to continue the existing inspections of the redesigned shaft assembly. Accordingly, the proposed rule is withdrawn.