AD 2021-16-11 Prompted By A Report Of Reduced Yaw Control, During An Approach For Landing

The FAA is adopting a new airworthiness directive (AD) for certain Airbus Helicopters Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350D, AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters.

This AD was prompted by a report of reduced yaw control, during an approach for landing, that resulted from rupture of  the tail rotor gearbox (TGB) actuating rod and uncoupling of the steel sleeve from inside the external aluminum tube. This AD requires dye penetrant inspecting certain TGB actuating rods for a crack, and depending on the inspection results, replacing the TGB actuating rod, as specified in a European Union Aviation Safety Agency (EASA) AD, which is incorporated by reference. The FAA is issuing this AD to address the unsafe condition on these products. This AD is effective October 6, 2021.

Supplementary Information: The EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2019-0060, dated March 20, 2019 (EASA AD 2019-0060) (also referred to as the Mandatory Continuing Airworthiness Information, or the MCAI), to correct an unsafe condition for all Airbus Helicopters Model AS350 B, AS350 BA, AS350 BB, AS350 B1, AS350 B2, AS350 B3, AS350 D, AS355 E, AS355 F, AS355 F1, AS355 F2, AS355 N and AS355 NP helicopters. Model AS350 BB helicopters are not certificated by the FAA and are not included on the U.S. type certificate data sheet; this AD therefore does not include those helicopters in the applicability.

Although EASA AD 2019-0060 applies to all helicopters identified in EASA AD 2019-0060, this AD applies to helicopters with an affected part installed instead.

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to certain Airbus Helicopters Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350D, AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters. The NPRM published in the Federal Register on May 18, 2021 (86 FR 26857).

The NPRM was prompted by a report of reduced yaw control, during an approach for landing, that resulted from rupture of the TGB actuating rod and uncoupling of the steel sleeve from inside the external aluminum tube. The NPRM proposed to require dye penetrant inspecting certain TGB actuating rods for a crack, and depending on the inspection results, replacing the TGB actuating rod, as specified in an EASA AD.

The FAA is issuing this AD to address failure of a TGB actuating rod, which could result in loss of yaw control of the helicopter. See the MCAI for additional background information.

FMI: www.regulations.gov