# AD 88-12-01: High Pressure Compressor Rear Shafts

- Type: Airworthiness directive
- Status: Current
- Products: General Electric CF6-6D, CF6-6D1, CF6-6D1A, CF6-6K and CF6-6K2
- Effective: June 6, 1988
- Superseded by: Nothing supersedes this AD
- Product type: Engine
- Amendment: 39-5933
- Registered aircraft: 11 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/B91ACB730675D6458625685F006F5CDB.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/88-12-01

## The airworthiness directive

88-12-01 GENERAL ELECTRIC: Amendment 39-5933. Applies to General Electric (GE) CF6-6 turbofan engines.

Compliance is required as indicated, unless already accomplished.

To prevent failure of high pressure compressor (HPC) rear shafts, and/or compressor discharge pressure (CDP) seal supports, accomplish the following:

  (a) Remove from service, HPC rear shafts, Part Numbers 9021M68G02 through 9021M68G04 inclusive; 9021M68G07 through 9021M68G09 inclusive; 9021M68G12; and 9021M68G13; and 1380M55G01 through 1380M55G06 inclusive, as follows:

  (1) Remove from service HPC rear shafts which have accumulated 17,600 or more cycles since new on the effective date of this AD, within the next 400 cycles in service.

  (2) Remove from service HPC rear shafts which have accumulated less than 17,600 cycles since new on the effective date of this AD, at or prior to accumulating 18,000 cycles since new.

  (b) Remove from service, CDP seal supports, Part Numbers 9686M62P02 through 9686M62P08 inclusive; and 9686M62P10, as follows:

  (1) Remove from service CDP seal supports which have accumulated 17,600 or more cycles since new on the effective date of this AD, within the next 400 cycles in service.

  (2) Remove from service CDP seal supports which have accumulated less than 17,600 cycles since new on the effective date of this AD at or prior to accumulating 18,000 cycles since new.

NOTE: This action establishes new life limits of 18,000 service cycles for the parts noted in (a) and (b) above. The new limits are published in Chapter 5 of the CF6-6 Maintenance and Shop manuals.

  (c) Aircraft may be ferried in accordance with the provisions of FAR 21.197 and 21.199 to a base where the AD may be accomplished.

  (d) Upon submission of substantiating data by an owner or operator through an FAA airworthiness inspector, the Manager, Engine Certification Office, New England Region, may adjust the compliance schedules specified in this AD.This amendment, 39-5933, becomes effective June 6, 1988.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS E23EA](https://openairdocs.org/tcds/E23EA): General Electric Company; names 5 of 18 models: CF6-6D1A, CF6-6D, CF6-6D1, CF6-6K, CF6-6K2

## 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: 11 (0 by airframe model, 11 by engine model)
- Makers: Boeing 6, Mcdonnell Douglas 3, Airbus Industrie 2

Models with the most aircraft:

- [GE CF6-6 series](https://openairdocs.org/engine/ge-cf6-6-series): 9 aircraft (engine model)
- [GE CF6-6D](https://openairdocs.org/engine/ge-cf6-6d): 2 aircraft (engine model)

All 2 models: https://openairdocs.org/ad/88-12-01/models.md
Every aircraft: https://openairdocs.org/ad/88-12-01/aircraft.md

Its text cites no advisory circulars or STCs.

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