EASA AD US-2018-02-10
SUPERSEDED BY FAA AD 2023-22-02
Summary
The Federal Aviation Administration Airworthiness Directive 2018-02-10 is a final rule addressing Pratt & Whitney Division PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 turbofan engines. It mandates inspections to detect cracks in the outer diffuser case and requires removal from service of any cases that fail inspection to ensure continued airworthiness and safety.
What Changed
This AD introduces mandatory initial and repetitive inspections of the outer diffuser case for cracks and requires removal of defective cases from service. It clarifies definitions such as 'engine disassembly' and accepts certain previous inspections as compliant. The AD does not adopt later revisions of the service bulletin but maintains the original inspection requirements.
Why It Matters
This directive is critical for aviation professionals as it addresses a known unsafe condition involving cracked outer diffuser cases that could compromise engine integrity. Operators and maintenance organizations must comply to prevent potential engine failures, ensuring flight safety and regulatory compliance. It also provides clarity on acceptable inspection methods and credit for prior inspections, aiding maintenance planning.
What To Do
Affected operators must perform initial and repetitive fluorescent penetrant inspections of the outer diffuser case as specified in Pratt & Whitney Alert Service Bulletin PW4G-112-A72-347 dated March 31, 2017. Inspections must be completed by February 26, 2018, and cases failing inspection must be removed from service. Operators should also note the definition of 'engine disassembly' and may credit prior inspections performed according to the service bulletin.
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