AD FAA-2010-0720

The FAA is withdrawing a notice of proposed rulemaking (NPRM) that proposed to adopt a new airworthiness directive (AD) that would have applied to certain Sikorsky Model S-92A helicopters. The NPRM was prompted by a fatigue analysis conducted after a helicopter was found with a severed main gearbox (MGB) mounting foot pad (foot pad) that failed due to fatigue. The NPRM would have required revising the airworthiness limitations section of the existing Instructions for Continued Airworthiness (ICA) for your helicopter to reduce the life limit of the MGB housing and replacing any MGB housing that exceeds the life limit. Since issuance of the NPRM, the FAA has determined that the affected MGB housings are no longer in service. Accordingly, the NPRM is withdrawn.