EASA AD US-2018-21-10
Engine - High-Pressure Turbine Stator Cases - Replacement
Summary
Federal Aviation Administration Airworthiness Directive 2018-21-10 is a final rule addressing all International Aero Engines (IAE) PW1133G-JM, PW1133GA-JM, PW1130G-JM, PW1127G-JM, PW1127GA-JM, PW1127G1-JM, PW1124G-JM, PW1124G1-JM, and PW1122G-JM turbofan engines. This directive requires replacement of specific parts related to the rear high-pressure compressor rotor hub knife edge seal to prevent in-flight engine shutdowns and aborted take-offs. It applies to engines with certain serial numbers and affected part numbers installed.
What Changed
This new airworthiness directive introduces mandatory replacement of the diffuser case air seal assembly, the high-pressure turbine second-stage vane assembly, and the high-pressure turbine second-stage borescope stator vane assembly with parts eligible for installation. It limits applicability to engines with serial numbers P770450 through P770614 that have the specified affected parts installed. The directive also clarifies compliance methods and confirms that incorporation of the related Pratt & Whitney Alert Service Bulletin satisfies the requirements.
Why It Matters
This directive is critical for aviation professionals to mitigate the risk of engine failures during flight or takeoff caused by durability issues in key engine components. Operators and maintenance organizations must ensure affected parts are identified and replaced at the next engine shop visit to maintain airworthiness and comply with FAA regulations. Compliance helps prevent operational disruptions and enhances flight safety for aircraft powered by the specified IAE engines.
What To Do
Operators must verify if their engines fall within the affected serial number range and have the specified part numbers installed. At the next engine shop visit, the diffuser case air seal assembly, HPT second-stage vane assembly, and HPT second-stage borescope stator vane assembly must be removed and replaced with approved parts. Compliance can be demonstrated by following Pratt & Whitney Alert Service Bulletin PW1000G-C-72-00-0099-00A-930A-D, Issue No. 002, dated March 15, 2018. The directive is effective December 12, 2018.
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