Engine - 4th Stage Low Pressure Turbine Air Seals - Replacement
- Published
- Effective
- Deadline
AI-generated summary of the official EASA document. Verify against the PDF before acting.
What to do
Affected operators must remove and replace the 4th stage LPT air seal P/N 50N346 with an approved replacement, P/N 51N113, the next time the 4th stage LPT vanes are removed from the module. They should follow the procedures outlined in Pratt & Whitney Service Bulletin PW4ENG A72-830, Revision No. 1. Compliance with this AD is mandatory by July 20, 2018, the effective date of the directive.
Summary
Federal Aviation Administration Airworthiness Directive 2018-13-02 is a final rule addressing Pratt & Whitney Division turbofan engines models PW4052, PW4056, PW4060, PW4062, PW4062A, PW4152, PW4156A, PW4158, PW4460, and PW4462, including suffixes -1C, -1E, -3, -3A, and -3B. It mandates the removal from service of certain 4th stage low-pressure turbine (LPT) air seals, specifically part number 50N346, due to the discovery of multiple cracks. The directive aims to prevent engine damage and potential airplane hazards caused by air seal failure.
What changed
This new airworthiness directive requires operators to remove and replace the affected 4th stage LPT air seals, P/N 50N346, at the next removal of the 4th stage LPT vanes from the module. Replacement must be with a part eligible for installation, currently P/N 51N113, which can be obtained by modifying the old part as per Pratt & Whitney Service Bulletin PW4ENG A72-830, Revision No. 1. The AD clarifies compliance times and installation prohibitions, and emphasizes that honeycomb replacement is governed by existing service information.
Why it matters
This AD is critical for aviation professionals because cracked 4th stage LPT air seals can lead to uncontained failures, causing engine damage and potential safety risks to aircraft. Operators and maintenance organizations must ensure compliance to maintain engine integrity and airworthiness. Understanding the specific part numbers and compliance requirements helps avoid inadvertent installation of unsafe components and ensures adherence to FAA safety standards.
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- EASA AD US-2019-06-02[Correction] Engine Fuel - Fuel Nozzle - ReplacementApr 24, 2019
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