AD Amdt-39-11334

Recurring final rule
Data completeness: 70%

Airworthiness Directives; Pratt & Whitney JT9D-7R4 Series Turbofan Engines

AD Number
Amdt-39-11334
Status
final_rule
Effective Date
Product Category
engine
Docket
Docket No. 99-NE-06-AD
FR Citation
64 FR 51683

Applicability

TypeManufacturerModelDetails
engine Pratt & Whitney JT9D-7R4 Series Airworthiness Directives; Pratt & Whitney JT9D-7R4 Series Turbofan Engines

Unsafe Condition

Subsurface anomalies in High Pressure Turbine (HPT) stage 1 and stage 2 disks, potentially formed during the forging process, could lead to HPT disk fractures, resulting in uncontained engine failure, airplane damage, and in-flight engine shutdown.

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

Required Actions

Inspect HPT stage 1 and stage 2 disks using an improved ultrasonic inspection method at an approved facility during a shop visit. If a crack indicating a subsurface anomaly is found, remove the disk from service and replace it with a serviceable part.

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

Compliance Time

Within the applicable maintenance interval or during the next shop visit where the disks are exposed.

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

Affected Aircraft

Pratt & Whitney JT9D-7R4 series turbofan engines, specifically HPT stage 1 and stage 2 disks.

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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