AD 2021-04-19 Prompted By Flight Testing And Fatigue Analysis Results

The FAA is adopting a new airworthiness directive (AD) for Bell Textron Inc. (Bell) Model 205B helicopters.

This AD was prompted by flight testing and fatigue analysis results. This AD requires reducing the life limit of certain tail rotor (T/R) blades and re-identifying them with a new part number (P/N). The FAA is issuing this AD to address the unsafe condition on these products. This AD is effective April 13, 2021.

Supplementary Information: The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to Bell Model 205B helicopters with a T/R blade P/N 212-010-750-009 or 212-010-750-105 installed. The NPRM published in the Federal Register on March 25, 2020 (85 FR 16916). Flight testing and fatigue analysis by Bell indicated that these part-numbered T/R blades sustain greater loads when installed on Bell Model 205B helicopters compared to their use on other model helicopters. In the NPRM, the FAA proposed to require, before further flight, reducing the life limit of each affected T/R blade from 5,000 hours time-in-service (TIS) to 2,500 hours TIS; reidentifying the T/R blade P/N on its data plate by vibro-etching to change the last three digits of the existing P/N; creating a component history card or equivalent record; and revising the Airworthiness Limitations section of the existing maintenance manual for your helicopter to annotate the new P/N and revised life limit. Finally, the NPRM proposed to prohibit installing any affected T/R blade that has not met the AD requirements.

The FAA issued a supplemental notice of proposed rulemaking (SNPRM) to amend 14 CFR part 39 by adding an AD that would apply to Bell Model 205B helicopters. The SNPRM published in the Federal Register on December 8, 2020 (85 FR 78977). The SNPRM was prompted by a comment received on the NPRM requesting that the applicability paragraph be updated to include newly identified T/R blade part numbers. The FAA determined the NPRM should be revised to include the additional part-numbered T/R blades and the re-identification and life limit requirements for those additional part-numbered T/R blades.

Since the FAA issued the NPRM, Bell Helicopter Textron Inc., has changed its name to Bell Textron Inc. This final rule reflects that change and updates the contact information to obtain service documentation.

FMI: www.regulations.gov