# AD 77-16-12: Low Turbine Shaft

- Type: Airworthiness directive
- Status: Current
- Products: Pratt & Whitney Division JT8D-1, JT8D-11, JT8D-15, JT8D-17, JT8D-1A, JT8D-1B, JT8D-7, JT8D-7A, JT8D-7B, JT8D-9 and JT8D-9A
- Effective: August 31, 1977
- Superseded by: Nothing supersedes this AD
- Product type: Engine
- Amendment: 39-3008
- Registered aircraft: 124 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/87851521D37366F98625685E0071E5A9.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/77-16-12

## The airworthiness directive

77-16-12 PRATT & WHITNEY AIRCRAFT: Amendment 39-3008. Applies to Pratt and Whitney Aircraft JT8D-1, -1A, -1B, -7, -7A, -7B, -9, -9A, -11, -15, and -17 turbofan engine models containing Number 4-1/2 bearing, P/N 707007, bearing Serial Numbers 800 through 999, and Serial Numbers 100A through 214A.

Compliance required as indicated. To preclude possible low turbine shaft failure, resulting from failure of the Number 4-1/2 bearing, remove from service, prior to March 31, 1978, Number 4-1/2 bearings, P/N 707007, Serial Numbers 800 through 999, and Serial Numbers 100A through 214A. Replace with an FAA approved, serviceable 4-1/2 bearing.

Affected bearings shipped in engines and shipped as spares are identified by serial number in Tables I and II of Pratt and Whitney Aircraft Alert Service Bulletin Number 4639, dated August 12, 1976, or later revision approved by the Chief, Engineering and Manufacturing Branch, New England Region.

Upon request of the operator, an FAA Maintenance Inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, FAA, New England Region, may adjust the compliance date specified in this A.D. to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increase for that operator.

The manufacturer's service bulletin identified and described in this directive is incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to Pratt and Whitney Aircraft, Division of United Technologies Corporation, 400 Main Street, East Hartford, Connecticut 06108. These documents may also be examined at Federal Aviation Administration, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803, and at FAA Headquarters, 800 Independence Avenue, S.W., Washington, D.C.

This amendment becomes effective August 31, 1977.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS E2EA](https://openairdocs.org/tcds/E2EA): Pratt & Whitney; names 11 of 16 models: JT8D-1, JT8D-15, JT8D-17, JT8D-7, JT8D-11, JT8D-9, JT8D-7A, JT8D-1B…

## 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: 124 (0 by airframe model, 124 by engine model)
- Makers: Mcdonnell Douglas 83, Boeing 37, Douglas 3, Beech 1

Models with the most aircraft:

- [Pratt & Whitney JT8D series](https://openairdocs.org/engine/pratt-whitney-jt8d-series): 82 aircraft (engine model)
- [Pratt & Whitney JT8D-9 series](https://openairdocs.org/engine/pratt-whitney-jt8d-9-series): 9 aircraft (engine model)
- [Pratt & Whitney JT8D-1](https://openairdocs.org/engine/pratt-whitney-jt8d-1): 8 aircraft (engine model)
- [Pratt & Whitney JT8D-17 series](https://openairdocs.org/engine/pratt-whitney-jt8d-17-series): 7 aircraft (engine model)
- [Pratt & Whitney JT8D-17](https://openairdocs.org/engine/pratt-whitney-jt8d-17): 6 aircraft (engine model)
- [Pratt & Whitney JT8D-15](https://openairdocs.org/engine/pratt-whitney-jt8d-15): 6 aircraft (engine model)
- [Pratt & Whitney JT8D-9A](https://openairdocs.org/engine/pratt-whitney-jt8d-9a): 5 aircraft (engine model)
- [Pratt & Whitney JT8D-9](https://openairdocs.org/engine/pratt-whitney-jt8d-9): 1 aircraft (engine model)

All 8 models: https://openairdocs.org/ad/77-16-12/models.md
Every aircraft: https://openairdocs.org/ad/77-16-12/aircraft.md

Its text cites no advisory circulars or STCs.

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