AD 2021-05-16
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Pratt & Whitney | Division | Airworthiness Directives; Pratt & Whitney Division Turbofan Engines |
Unsafe Condition
LPT 4th-stage vane cluster assemblies leaning back and notching into rotating LPT 4th-stage blades, causing some blades to fracture and release.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Initial and repetitive replacements of the LPT 4th-stage air sealing ring segment assemblies with parts eligible for installation, and initial and repetitive dimensional inspections of the LPT case for bulging, with repair or replacement of the LPT case depending on the results of the inspection.
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Compliance Time
Before further flight
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Affected Aircraft
Certain Pratt & Whitney Division (PW) PW4164, PW4164-1D, PW4168, PW4168-1D, PW4168A, PW4168A-1D, and PW4170 model turbofan engines.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 4, 2026
Rights: U.S. Government Public Domain
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