AD 2021-14-15 Required Removing Certain Main Rotor Head Torsion Tie Bars From Service

The FAA is superseding Airworthiness Directive (AD) 2002-08-16 for certain Eurocopter France SA341G, SA342J, and SA-360C helicopters.

AD 2002-08-16 required removing certain main rotor head torsion tie bars (tie bars) from service and revising the limitations section of the existing maintenance manual for your helicopter by adding life limits for certain other tie bars. This AD was prompted by the determination that another part-numbered tie bar is affected by the same unsafe condition. This AD continues to require removing certain tie bars from service and establishing a life limit for certain other tie bars. The FAA is issuing this AD to address the unsafe condition on these products. This AD is effective August 10, 2021.

Supplementary Information: The FAA issued a supplemental notice of proposed rulemaking (SNPRM) to amend 14 CFR part 39 to supersede AD 2002-08-16 (67 FR 19640, April 23, 2002) (AD 2002-08-16). AD 2002-08-16 applied to Eurocopter France Model SA341G, SA342J, and SA-360C helicopters with a tie bar part number (P/N) 341A31-4904-00, -01, -02, -03; 341A31-4933-00, -01; or 360A31-1097-02, -03, installed. The SNPRM published in the Federal Register on May 20, 2021 (86 FR 27323). The FAA preceded the SNPRM with a notice of proposed rulemaking (NPRM) that published in the Federal Register on May 10, 2006 (71 FR 27215). The SNPRM proposed to continue to require removing tie bar P/Ns 341A31-4904-00, -01, -02, and -03; and 360A31-1097-02 and -03 from service. The SNPRM also proposed to prohibit installing those part-numbered tie bars on any helicopter. The SNPRM proposed to initially require removing tie bar P/Ns 341A31-4933-00 and -01; and 704A33-633-270 from service if they have accumulated or exceeded the specified life limit, and thereafter removing those part-numbered tie bars from service before accumulating the specified life limit.

The SNPRM was prompted by a significant amount of time that had elapsed since issuance of the NPRM that required the FAA to reopen the comment period to allow the public a chance to comment on the proposed actions. Additional review also revealed necessary changes to address the unsafe condition. The SNPRM proposed to clarify that the compliance times of requirements continued from AD 2002-08-16 are effective after the effective date of AD 2002-08-16, clarify instances of life limits specified in calendar time that they are since initial installation of the tie bar on any helicopter, clarify one instance of a life limit that it is total hours time-in-service (TIS) or calendar time–whichever occurs first, and add parts installation prohibitions. The SNPRM also updated the AD format. As a result, paragraph identifiers changed, editorial changes were made to meet current publishing requirements, and the proposed requirements were revised by removing unnecessary information.

The NPRM was prompted by DGAC AD 2001-587-041(A) R2, dated January 8, 2003 (DGAC AD 2001-587-041(A) R2), issued by the DGAC, which was the Technical Agent for France, to correct an unsafe condition for Model SA 341/342 helicopters. The DGAC advised of another affected tie-bar P/N 704A33-633-270 and additional flight restrictions for the newly-affected tie bar.

This condition, if not addressed, could result in failure of a tie bar and subsequent loss of control of the helicopter. Accordingly, DGAC AD 2001-587-041(A) R2, along with DGAC AD 2001-588-047(A) R1, dated December 26, 2001 (DGAC AD 2001-588-047(A) R1), for Model SA 360 helicopters, require removing certain part-numbered tie bars from service and a life limit for certain other part-numbered tie bars.

FMI: www.regulations.gov