EASA AD 2021-0052
SUPERSEDED BY EASA AD 2021-0154
Summary
EASA Airworthiness Directive 2021-0052 is an airworthiness directive addressing GE Aviation Czech M601 series engines installed on various aircraft including the LET L-410 series, Air Tractor AT series, Grumman G-164, PZL-106, Dornier Do 28, Thrush S-2R, DHC-3 Otter, Zlin Z-37T, and PAC FU-24. The directive focuses on the replacement and life limit implementation of propeller shafts, specifically part numbers M601-6081.2, M601-6081.4, and M601-6081.6. It mandates compliance to ensure continued airworthiness and prevent propeller shaft failure.
What Changed
EASA Airworthiness Directive 2021-0052 introduces mandatory replacement of certain propeller shafts on M601 engine models within specified flight hour limits. It establishes life limits for propeller shafts where none were previously published and requires operators to replace non-approved propeller shafts within 30 flight hours. The directive also clarifies installation rules for serviceable propeller shafts and provides detailed grouping of affected engines and parts.
Why It Matters
This directive is critical for aviation professionals as it addresses a safety risk related to propeller shaft failures that could lead to propeller detachment and loss of aircraft control. Operators and maintenance organizations must ensure compliance to avoid unsafe conditions and potential accidents. It also affects maintenance planning and parts management by introducing new life limits and replacement requirements.
What To Do
Operators must replace propeller shafts on Group 1 engines within 30 flight hours after 3 March 2021 with approved serviceable parts. For Group 2 and Group 3 engines, propeller shafts must be replaced before exceeding the defined life limits of 9,000 or 12,000 flight hours depending on the part number. From the effective date, only serviceable propeller shafts may be installed, and all replacements must follow the instructions in the GE Aviation Czech Alert Service Bulletin.
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