EASA AD US-2021-18-13
Engine - Combustion Outer Liner Shell - Inspection / Replacement
Summary
The Federal Aviation Administration Airworthiness Directive 2021-18-13 is a final rule addressing all General Electric Company CF34-8 model turbofan engines equipped with a specific combustion outer liner shell. This directive mandates inspections and potential replacement of the combustion outer liner shell due to failures that caused two in-flight engine shutdowns. It applies to various CF34-8C and CF34-8E engine variants and aims to mitigate unsafe conditions related to combustion liner shell cracking and collapse.
What Changed
This new airworthiness directive introduces mandatory borescope or visual inspections of the combustion outer liner shell on affected GE CF34-8 engines, with replacement required if defects are found. It updates references to the latest revisions of GE Alert Service Bulletins 72-A0221 R02 and 72-A0335 R02 and clarifies inspection compliance timing. The directive also establishes installation prohibitions for combustion outer liner shells exceeding specified flight hour limits.
Why It Matters
This AD is critical for aviation professionals as it addresses a safety risk that led to engine shutdowns during flight, potentially preventing catastrophic engine failures. Operators and maintenance organizations must incorporate these inspections into their maintenance schedules to ensure continued airworthiness and regulatory compliance. The directive also impacts maintenance planning and cost considerations due to inspection and possible replacement requirements.
What To Do
Operators of aircraft with GE CF34-8 series engines must perform a borescope or visual inspection of the combustion outer liner shell before accumulating 500 engine flight hours past 17,500 flight hours since new or repair. If inspection reveals damage, the combustion outer liner shell must be replaced. Installation of combustion outer liner shells with more than 17,500 flight hours since new or repair is prohibited without prior inspection. Compliance with this directive is required by October 22, 2021.
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