AD 2021-24-20 Prompted By Reports Of Slat Transmission Jams Caused By Frozen Slat Geared Rotary Actuators

The FAA is adopting a new airworthiness directive (AD) for all Airbus SAS Model A350-941 and -1041 airplanes.

This AD was prompted by reports of slat transmission jams caused by frozen slat geared rotary actuators (SGRAs) at slat 5 track 12. This AD requires repetitive water drainage and plug cleaning of the left- and right-hand SGRAs having a certain part number installed on slat 5 track 12 with certain functional item numbers, 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 January 27, 2022.

Supplementary Information: EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2021-0130R1, dated June 10, 2021 (EASA AD 2021-0130R1) (also referred to as the MCAI), to correct an unsafe condition for all Airbus SAS Model A350-941 and -1041 airplanes.

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to all Airbus SAS Model A350-941 and -1041 airplanes. The NPRM published in the Federal Register on September 23, 2021 (86 FR 52848). The NPRM was prompted by reports of slat transmission jams caused by frozen SGRAs at slat 5 track 12. Further investigation showed that the jams occur when water in the SGRA freezes due to low temperature during cruise and insufficient water drainage. The NPRM proposed to require repetitive water drainage and plug cleaning of the left- and right-hand SGRAs having a certain part number installed on slat 5 track 12 with certain functional item numbers, as specified in EASA AD 2021-0130R1.

The FAA is issuing this AD to address SGRA jams, which could result in reduced control of the airplane. See the MCAI for additional background information.

FMI: www.regulations.gov