Summary
The FAA is withdrawing a notice of proposed rulemaking (NPRM) that proposed to supersede Airworthiness Directive (AD) 2011-18-52, which applies to certain Agusta Model AB139 and AW139 helicopters. AD 2011-18-52 requires establishing a revised life limit for each tail rotor blade (blade), updating the existing historical records for your helicopter, repetitively inspecting each blade for a crack, and replacing certain blades. The NPRM was prompted by the manufacturer developing an improved blade using different materials and establishing life limits for those newly-designed blades. The NPRM proposed to require expanding the applicability to include the newly-designed blades and establish their life limits, and proposed to retain the requirement to inspect each blade for a crack and, if there is a crack, replace each blade with an airworthy blade. Since issuance of the NPRM, the FAA has determined that the NPRM does not adequately address the identified unsafe condition. Accordingly, the NPRM is withdrawn.