# AD 75-04-07: Tenth Stage Compressor Disk

- Type: Airworthiness directive
- Status: Current
- Products: Pratt & Whitney Division JT3D-3, JT3D-3B and JT3D-7
- Effective: February 19, 1975
- Superseded by: Nothing supersedes this AD
- Product type: Engine
- Amendment: 39-2084
- Registered aircraft: 5 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/9822411EFBAF7E248625685B0070D060.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/75-04-07

## The airworthiness directive

75-04-07 PRATT & WHITNEY AIRCRAFT: Amendment 39-2084. Applies to all Pratt & Whitney Aircraft JT3D-3, JT3D-3B, and JT3D-7 turbofan engines containing tenth stage compressor disk, P/N 701810.

Compliance required as indicated.

To ensure adequate life limit margin for tenth stage compressor disk, P/N 701810, the cyclic life limits on these disks have been reduced below the figures currently approved. Unless already accomplished, remove from service the tenth stage compressor disk prior to exceeding the revised life limit listed below or within the next 25 cycles in service after the effective date of this AD, whichever comes later.

Engine Model Previous Life Limit (Cycles) Revised Life Limit (Cycles) JT3D-3 30,000 25,000 JT3D-3B 30,000 25,000 JT3D-7 25,000 23,000

If a disk has been used in more than one engine model, the disk is limited to the lowest cyclic life permitted for the engine models in which it has been exposed.

This amendment becomes effective February 19, 1975.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 1E8](https://openairdocs.org/tcds/1E8): Pratt & Whitney Division; names 3 of 11 models: JT3D-3, JT3D-7, JT3D-3B

## Registered aircraft it may apply to (OpenAirDocs)

Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment.

- Aircraft: 5 (0 by airframe model, 5 by engine model)
- Makers: Boeing 3, Mcdonnell Douglas 2

Models with the most aircraft:

- [Pratt & Whitney JT3D-3B](https://openairdocs.org/engine/pratt-whitney-jt3d-3b): 3 aircraft (engine model)
- [Pratt & Whitney JT3D series](https://openairdocs.org/engine/pratt-whitney-jt3d-series): 2 aircraft (engine model)

All 2 models: https://openairdocs.org/ad/75-04-07/models.md
Every aircraft: https://openairdocs.org/ad/75-04-07/aircraft.md

Its text cites no advisory circulars or STCs.

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