AD FAA-2005-21679

The FAA is withdrawing a notice of proposed rulemaking (NPRM) that proposed to adopt a new airworthiness directive (AD) that would have applied to Robinson Helicopter Company (RHC) Model R22 series helicopters. The NPRM was prompted by an in-flight break up of a helicopter on which both teeter stop brackets (brackets) failed. The NPRM would have required replacing each main rotor blade (blade) droop and teeter stop (stop) and bracket and associated hardware with redesigned and improved airworthy parts. Since issuance of the NPRM, the FAA has determined that failure of the brackets was caused by turbulence and other factors that are addressed in AD 95-26-04. Accordingly, the NPRM is withdrawn.