AD 2020-25-01 Requires A One-Time Inspection For The Presence Of Washer Part Number (P/N) 90-380058-1

The FAA is adopting a new airworthiness directive (AD) for certain Textron Aviation Inc. (Textron) (type certificate previously held by Beechcraft Corporation) Models F90, 65-90, 65-A90, B90, C90, H90 (T-44A), E90, 65-A90-1 (JU-21A, U-21A, RU-21A, RU-21D, U-21G, RU21H), 65-A90-2 (RU-21B), 65-A90-3 (RU-21C), 65-A90-4 (RU-21E, RU-21H), 99, 99A, 99A (FACH), A99, A99A, B99, C99, 100, A100 (U-21F), and B100 airplanes.

This AD was prompted by reports of fatigue cracks in the lower forward wing fitting. This AD requires a one-time inspection for the presence of washer part number (P/N) 90-380058-1 on the left-hand (LH) and right-hand (RH) lower forward wing bolt and, if applicable, removing washer P/N 90-380058-1, inspecting the wing fitting, bolt, and nut, replacing the wing fitting if it is cracked, and replacing the washer with washer P/N 90-380019-1. The FAA is issuing this AD to address the unsafe condition on these products. This AD is effective January 11, 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 certain Textron (type certificate previously held by Beechcraft Corporation) Models F90, 65-90, 65-A90, B90, C90, H90 (T-44A), E90, 65-A90-1 (JU-21A, U-21A, RU-21A, RU-21D, U-21G, RU-21H), 65-A90-2 (RU-21B), 65-A90-3 (RU-21C), 65-A90-4 (RU21E, RU-21H), 99, 99A, 99A (FACH), A99, A99A, B99, C99, 100, A100 (U-21F), and B100 airplanes. The NPRM published in the Federal Register on July 29, 2020 (85 FR 45545).

The NPRM was prompted by Textron receiving reports of fatigue cracks in the lower forward wing fitting on two airplanes. Investigation revealed that installing washer P/N 90-380058-1 on the wing bolt will cause a premature torque indication. This washer may have been installed as part of kit 101-4024-3 on Models F90, 65-90, 65-A90, B90, C90, H90 (T-44A), E90, 65-A90-1 (JU-21A, U21A, RU-21A, RU-21D, U-21G, RU-21H), 65-A90-2 (RU-21B), 65-A90-3 (RU-21C), 65-A90-4(RU-21E, RU-21H), 99, 99A, 99A (FACH), A99, A99A, B99, C99, 100, A100 (U-21F), and B100 airplanes, or as part of kit 90-4077-1 on Models 65-90, 65-A90, 65-A90-1 (JU-21A, U-21A, RU21A, RU-21D, U-21G, RU-21H), 65-A90-2 (RU-21B), 65-A90-3 (RU-21C), 65-A90-4 (RU-21E, RU-21H), B90, C90, and E90 airplanes. Under-torque of the wing bolt causes a reduced clamping force that changes the load path reacted by the RH and LH lower forward wing fitting.

In the NPRM, the FAA proposed to require a one-time inspection for the presence of washer P/N 90-380058-1 on the LH and RH lower forward wing bolt and, if applicable, removing washer P/N 90-380058-1, inspecting the wing fitting, bolt, and nut, replacing the wing fitting if it is cracked, and replacing the washer with washer P/N 90-380019-1. This condition, if not addressed, could result in fatigue cracks that lead to failure of the forward lower wing fitting, wing separation, and loss of airplane control.

FMI: www.regulations.gov