AD Amdt-39-11220

final rule
Data completeness: 70%

Airworthiness Directives; Pratt & Whitney PW4000 Series Turbofan Engines

AD Number
Amdt-39-11220
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Docket No. 97-ANE-55-AD
FR Citation
64 FR 38301

Applicability

TypeManufacturerModelDetails
engine Pratt & Whitney PW4000 Series Airworthiness Directives; Pratt & Whitney PW4000 Series Turbofan Engines

Unsafe Condition

A change in the cooling hole geometry of certain 4th stage low pressure turbine (LPT) disks inadvertently reduced cooling airflow and increased stress levels, potentially leading to an uncontained disk failure and damage to the aircraft.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Inspect and reduce the life limits of certain 4th stage LPT disks. Alternatively, restore original life limits if reoperation is performed to incorporate the original slotted cooling hole configuration.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Before further flight

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

Pratt & Whitney PW4000 series turbofan engines with certain 4th stage LPT disks affected by the altered cooling hole geometry.

AI-generated summary from the source AD text. Verify against the official source before acting.

Source: Official FAA Source ↗

Retrieved: Apr 6, 2026

Rights: U.S. Government Public Domain

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