Engine - Low Pressure Turbine Rotor Stage 3 Disks - Inspection / Removal / Replacement
- Published
- Effective
- Deadline
- Replaces
- 2012-02-07
AI-generated summary of the official EASA document. Verify against the PDF before acting.
What to do
Affected operators must perform initial and repetitive borescope inspections of HPT and LPT rotor blades within specified cycle limits and after certain engine events. They must conduct vibration surveys and engine checks as required, and ultimately remove and replace the affected LPT rotor stage 3 disks with the redesigned part number 2453M80P01 by the revised drawdown plan deadlines. Installation or reinstallation of prohibited disk part numbers is not allowed. Compliance with these actions is mandatory by April 28, 2023.
Summary
The document titled "Engine - Low Pressure Turbine Rotor Stage 3 Disks - Inspection / Removal / Replacement" is a Federal Aviation Administration (FAA) Airworthiness Directive (AD 2023-04-11) addressing certain General Electric Company CF6-45 and CF6-50 series turbofan engines. It mandates inspections and replacement requirements for low-pressure turbine (LPT) rotor stage 3 disks to prevent unsafe conditions caused by rotor assembly separations. The directive applies to specific engine models with affected LPT rotor stage 3 disk part numbers.
What changed
This AD supersedes the previous AD 2012-02-07, introducing a redesigned LPT rotor stage 3 disk with improved fatigue resistance and requiring its mandatory removal and replacement. It revises inspection requirements to include borescope inspections of high-pressure turbine (HPT) and LPT rotor blades, vibration surveys, and enforces a lower life limit for the affected disks. The AD also prohibits installation or reinstallation of certain LPT rotor stage 3 disks and updates the compliance timeline for the drawdown plan.
Why it matters
This AD is critical for aviation professionals as it addresses the risk of uncontained engine failures due to LPT rotor assembly separations, which can cause significant safety hazards and aircraft damage. Operators and maintenance organizations must comply to ensure continued airworthiness and prevent in-service failures. The directive also impacts maintenance planning and parts management by mandating replacement with redesigned components and updated inspection protocols.
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New ADs and bulletins for General Electric CF6-45 and Electric CF6-50, summarized like this page, every Monday.