Superseded by FAA AD 2021-22-14
- Published
- Effective
- Deadline
AI-generated summary of the official EASA document. Verify against the PDF before acting.
What to do
Affected operators must perform the required initial and repetitive replacements of the LPT 4th-stage air sealing ring segment assemblies and conduct dimensional inspections of the LPT case for bulging. If inspections reveal damage, repair or replacement of the LPT case must be carried out using approved methods. All actions must be completed by the effective date of May 7, 2021, and repeated as specified in the directive.
Summary
FAA Airworthiness Directive 2021-05-16 is a final rule affecting Pratt & Whitney PW4164, PW4164-1D, PW4168, PW4168-1D, PW4168A, PW4168A-1D, and PW4170 turbofan engines equipped with specific low-pressure turbine (LPT) 4th-stage air sealing ring segment assemblies. This directive addresses unsafe conditions caused by LPT 4th-stage vane cluster assemblies leaning back and damaging rotating blades, which can lead to blade fractures and releases. The AD mandates inspections and replacements to ensure engine safety and reliability.
What changed
This new airworthiness directive introduces mandatory initial and repetitive replacements of the LPT 4th-stage air sealing ring segment assemblies with approved parts. It also requires initial and repetitive dimensional inspections of the LPT case for bulging, with repair or replacement actions based on inspection results. The AD clarifies definitions related to engine shop visits and confirms that any approved repair methods may be used to restore the LPT case.
Why it matters
This AD is critical for aviation professionals because it prevents potentially catastrophic engine failures caused by damaged turbine components. Operators and maintenance organizations must comply to avoid uncontained blade releases, which pose safety risks and can lead to costly unscheduled maintenance and operational disruptions. Compliance ensures continued airworthiness and reduces the risk of in-flight engine malfunctions.
More for Pratt & Whitney PW4100
All 4- EASA AD US-2021-22-14Engine - Low-Pressure Turbine - Replacement / InspectionDec 10, 2021
- EASA AD US-2020-25-09Engine - 3rd Stage Low-pressure Turbine Duct Segments - Removal / ReplacementDec 11, 2020
- EASA AD US-2019-06-07Engine Fuel & Control - Fuel Nozzles and Supply Manifold Assemblies - Inspection / Replacement / ModificationMar 29, 2019
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New ADs and bulletins for Pratt & Whitney PW4100, summarized like this page, every Monday.