EASA AD 2021-0154
SUPERSEDED BY EASA AD 2023-0020
Summary
EASA Airworthiness Directive 2021-0154 is an airworthiness directive addressing GE Aviation Czech M601 series engines installed on various aircraft including Aircraft Industries L-410 and L-420, Air Tractor AT series, Grumman G-164, PZL-106, Dornier Do 28, Thrush S-2R, Viking DHC-3 Otter, Zlin Z-37T, and PAC FU-24. The directive mandates replacement and life limit implementation for propeller shafts with specific part numbers to ensure continued airworthiness and prevent potential propeller shaft failure.
What Changed
EASA AD 2021-0154 supersedes AD 2021-0052 and introduces updated affected engine groups and revised compliance times based on new data regarding propeller shaft accumulated life. It partially retains previous requirements but extends compliance times for Group 1 engines and clarifies life limits for propeller shafts not previously published in the Airworthiness Limitation Section.
Why It Matters
This directive is critical for aviation professionals to prevent propeller shaft failure that could lead to propeller detachment, engine damage, and loss of aircraft control. Operators and maintenance organizations must ensure compliance to maintain aircraft safety and regulatory conformity. Accurate life tracking and timely replacement of propeller shafts are essential to avoid unsafe conditions and potential accidents.
What To Do
Operators must replace propeller shafts on Group 1 engines within 350 flight hours after 3 March 2021 or before exceeding 12,000 flight hours since first installation, whichever occurs first. For Group 2 and 3 engines, replacement must occur before exceeding the applicable life limit. Only serviceable propeller shafts may be installed, and these must be replaced before reaching their life limit. Compliance must follow the instructions in the GEAC Alert Service Bulletin revisions up to 02 dated 31 May 2021.
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