EASA AD US-2021-17-09
Engine - High-Pressure Compressor Front Hub and Rotor Shaft - Removal / Replacement
Summary
The Federal Aviation Administration's Airworthiness Directive 2021-17-09 is a final rule addressing Pratt & Whitney PW1500G and PW1900G series turbofan engines. It mandates the removal and replacement of the high-pressure compressor (HPC) front hub and HPC rotor shaft due to reported cracks that caused in-flight shutdowns and unscheduled engine removals. This directive aims to enhance engine safety and reliability for affected aircraft using these engines.
What Changed
This new airworthiness directive introduces a mandatory requirement to remove and replace specific HPC front hub and rotor shaft parts on all affected Pratt & Whitney PW1500G and PW1900G engine models. It incorporates redesigned components with improved durability and vibration stress distribution to prevent cracking. The directive is a new regulation rather than an amendment, establishing compliance obligations for operators.
Why It Matters
This directive is critical for aviation professionals because it addresses a safety risk that could lead to engine failure and potential damage to aircraft. Operators and maintenance organizations must ensure affected engines are inspected and upgraded to prevent in-flight shutdowns and unscheduled removals. Compliance ensures continued airworthiness and reduces operational disruptions caused by engine reliability issues.
What To Do
Operators must remove and replace the HPC front hub and HPC rotor shaft with eligible parts at the next engine shop visit after September 22, 2021, the effective date of the directive. Maintenance teams should follow the procedures outlined in Pratt & Whitney service bulletins for the removal and replacement process. Requests for alternative methods of compliance can be submitted to the FAA's ECO Branch as specified.
AI-generated summary from official EASA source document. Always verify against the original.