Summary
The FAA is withdrawing a notice of proposed rulemaking (NPRM) that proposed to supersede Airworthiness Directive (AD) AD 2002-20-01, which applies to certain Model HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH- 1E, UH-1F, UH-1H, UH-1L, and UH-1P helicopters; and Southwest Florida Aviation Model SW204, SW204HP, SW205, and SW205A-1 helicopters, manufactured by Bell Helicopter Textron, Inc. (BHTI) for the Armed Forces of the United States. The NPRM would have required removing certain serial-numbered tension-torsion (TT) straps from service, reducing the retirement life for other TT straps, and establishing a retirement life in terms of calendar time in addition to hours time-in- service (TIS) for certain other affected TT straps. The NPRM also would have added two model helicopters to the applicability of the AD. The NPRM was prompted by fatigue cracking in certain TT straps that have stainless steel filament windings and a determination that corrosion damage,which is related to calendar time, necessitated a calendar time retirement life for certain TT straps in addition to the retirement life based on hours TIS. The NPRM was also prompted by fatigue cracking in other TT straps with encased thin stainless steel plates. Since issuance of the NPRM, the FAA has re-reviewed the available information and determined that the totality of the available information does not support issuance of a final rule. Accordingly, the NPRM is withdrawn.