EASA AD 2022-0134: Propeller — Blade Lag Screws — Replacement

What to do

Operators must replace all affected blade lag screws with serviceable parts within the specified compliance times: within 4 months or 50 flight hours for turboprop engines, and within 2 months or 25 flight hours for piston engines, whichever occurs first after 20 July 2022. Installation of only serviceable lag screws is permitted from the effective date. Compliance can be credited if replacement was done before the effective date according to earlier revisions of the MT-Propeller Service Bulletin No. 30.

Summary

EASA Airworthiness Directive 2022-0134 is an airworthiness directive addressing the replacement of blade lag screws on MT-Propeller Entwicklung GmbH MTV variable pitch propellers installed on a wide range of aircraft including models from Piper, Airbus Defence & Space, Cirrus, Diamond, Textron Aviation, and others. The directive targets propellers and blades with specific serial numbers identified in MT-Propeller Alert Service Bulletin No. 30 Revision 7. It aims to ensure continued airworthiness by mandating replacement of affected lag screws to prevent potential in-flight blade detachment.

What changed

EASA Airworthiness Directive 2022-0134 introduces a mandatory replacement of non-conforming blade lag screws, part number A-983-C-85, with serviceable screws, part numbers A-983-D-85 or A-983-E-85, on affected MT-Propeller variable pitch propellers and blades. This AD is a new regulation prompted by the discovery of improperly finished screws produced between November 2013 and October 2014, which have reduced fatigue strength and pose a safety risk.

Why it matters

This directive is critical for aviation professionals because the affected lag screws could fail in service, leading to blade detachment and potential loss of aircraft control. Operators, maintenance organizations, and compliance teams must address this unsafe condition promptly to maintain aircraft safety and regulatory compliance. Failure to comply could result in grounding of affected aircraft or increased risk during flight operations.