AD 2021-18-01 Requires Repetitively Inspecting The Rudder Final Drive Rod Assembly

The FAA is adopting a new airworthiness directive (AD) for B-N Group Ltd. Models BN-2, BN-2A, BN-2A-2, BN-2A-3, BN-2A-6, BN-2A-8, BN-2A-9, BN-2A-20, BN-2A-21, BN-2A26, BN-2A-27, BN-2B-20, BN-2B-21, BN-2B-26, BN-2B-27, BN-2T, and BN-2T-4R airplanes.

This AD was prompted by mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI identifies the unsafe condition as failure of the rudder final drive rod because of cracks in the region of the taper pins. This AD requires repetitively inspecting the rudder final drive rod assembly and replacing the rudder final drive assembly, if necessary. The FAA is issuing this AD to address the unsafe condition on these products. This AD is effective October 14, 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 B-N Group Ltd. Models BN-2, BN-2A, BN-2A-2, BN-2A-3, BN-2A-6, BN-2A-8, BN-2A-9, BN-2A-20, BN-2A-21, BN-2A-26, BN-2A-27, BN-2B-20, BN-2B-21, BN-2B26, BN-2B-27, BN-2T, and BN-2T-4R airplanes. The NPRM published in the Federal Register on June 25, 2021 (86 FR 33576). The NPRM was prompted by MCAI originated by the European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union. EASA has issued EASA AD 2018-0153, dated July 19, 2018 (referred to after this as “the MCAI”), to address an unsafe condition on certain B-N Group Ltd. (Britten-Norman Aircraft Ltd., or “BNA”) Models BN-2, BN-2A, BN-2B, BN-2T, BN-2T-2, BN-2T-2R, and BN-2T-4R airplanes.

The MCAI states:

• Occurrences have been reported of failures of the rudder final drive rod, [part number] P/N NB45-0991. Cracks were found in the region of the taper pins. There is evidence that replacing the taper pins could be a significant factor contributing to the failure of this rod.
• This condition, if not detected and corrected, could lead to failure of the affected part, possibly resulting in reduced control of the aeroplane.
• To address this potential unsafe condition, BNA issued the applicable SB [service bulletin], providing inspection instructions. Prompted by operator comments, BNA revised the applicable SB (issue 3) to introduce repetitive inspections.
• For the reason described above, this [EASA] AD requires repetitive inspections of the affected part and, depending on findings, replacement. This AD also prohibits replacement of taper pins on an affected part. BNA will amend the applicable Maintenance Manuals accordingly.

You may examine the MCAI in the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-0502.

FMI: www.regulations.gov