AD 2021-10-18 Requires Inspecting Certain Collective Lever Switch Units For Discrepancies

The FAA is adopting a new airworthiness directive (AD) for certain Airbus Helicopters Deutschland GmbH Model MBB-BK117 D-2 helicopters.

This AD was prompted by reports that collective lever switch units having certain part numbers did not have retaining rings installed in the cable cut switch guard. This AD requires inspecting certain collective lever switch units for discrepancies (missing retaining rings, incorrectly installed retaining rings, and a missing axis in the cable cut switch guard), doing all applicable corrective actions, and marking affected parts, 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 July 6, 2021.

Supplementary Information: The EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2020-0084, dated April 3, 2020 (EASA AD 2020-0084) (also referred to as the Mandatory Continuing Airworthiness Information, or the MCAI), to correct an unsafe condition for all Airbus Helicopters Deutschland GmbH Model MBB-BK117 D-2 helicopters. Although EASA AD 2020-0084 applies to all Model MBB-BK117 D-2 helicopters, 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 Model MBB-BK117 D-2 helicopters. The NPRM published in the Federal Register on March 8, 2021 (86 FR 13234). The NPRM was prompted by reports that collective lever switch units having certain part numbers did not have retaining rings installed in the cable cut switch guard. The NPRM proposed to require inspecting certain collective lever switch units for discrepancies (missing retaining rings, incorrectly installed retaining rings, and a missing axis in the cable cut switch guard), doing all applicable corrective actions, and marking affected parts.

The cable cut switch guard has an axis that holds, and allows the guard to turn over, the cable cut switch. This axis is secured with two retaining rings and if both retaining rings are missing, the axis can move out. The FAA is issuing this AD to address this condition, which could cause inadvertent activation of the rescue hoist cable cut function, resulting in personal injury. See the MCAI for additional background information.

FMI: www.regulations.gov