EASA AD US-2022-21-06
Engine - Low Pressure Turbine Stage 5 Discs - Removal / Replacement
Summary
The Federal Aviation Administration's Airworthiness Directive 2022-21-06 addresses certain General Electric Company CF34-8C and CF34-8E model turbofan engines. It focuses on the removal and replacement of the low-pressure turbine (LPT) stage 5 disk, part number 4117T14P02, due to a reported crack in the forward arm area. This directive aims to ensure continued airworthiness and safety of affected engines.
What Changed
This new airworthiness directive requires operators to remove the affected LPT stage 5 disk once it reaches 8,000 cycles since new during the next piece-part exposure and replace it with a part eligible for installation, specifically part number 4117T14P03 or later approved parts. It prohibits installation of the affected disk with 8,000 or more cycles since new into the engine. This AD introduces mandatory compliance measures to mitigate the unsafe condition.
Why It Matters
This directive is critical for aviation professionals as it prevents potential failure of the LPT stage 5 disk, which could lead to loss of engine thrust control and reduced airplane control. Operators, maintenance, repair, and overhaul (MRO) organizations must ensure timely compliance to maintain engine reliability and safety. Compliance teams need to track affected parts and cycles to avoid installation of non-compliant components.
What To Do
Affected operators must remove and replace the LPT stage 5 disk, part number 4117T14P02, during the next piece-part exposure after the disk accumulates 8,000 cycles since new. Installation of disks with 8,000 or more cycles since new is prohibited. Compliance with this directive is mandatory by November 15, 2022, the effective date of the AD.
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