# AD 70-26-05: First Stage Compressor Rotor Blades

- Type: Airworthiness directive
- Status: Current
- Products: Pratt & Whitney Division JT8D-1, JT8D-11, JT8D-15, JT8D-15A, JT8D-17, JT8D-17A, JT8D-17AR, JT8D-17R, JT8D-1A, JT8D-1B, JT8D-209, JT8D-217 and 9 more
- Effective: December 29, 1970
- Superseded by: Nothing supersedes this AD
- Product type: Engine
- Amendment: 39-1131
- Registered aircraft: 150 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/FBB06AE4F6FF10E28625685B00661EBA.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/70-26-05

## The airworthiness directive

70-26-05 PRATT & WHITNEY AIRCRAFT: Amdt. 39-1131. Applies to all model JT8D series turbofan engines.

Compliance required as indicated.

To prevent failure of the first stage compressor rotor blades as the result of improperly machined blade roots, accomplish the following:

  (a) Within the next 900 hours in service after the effective date of this AD, unless already accomplished, visually inspect all P/N 487801, 511901 change letter L or earlier, 594601 and 616601 change letter B or earlier first stage compressor rotor blades, for tool marks within the radius of the Z plane platform on both sides of the blade root area. If tool marks are observed, replace the blade.

  (b) Upon submission of substantiating data through an FAA Maintenance Inspector by an owner or operator to the Chief, Engineering and Manufacturing Branch, FAA Eastern Region, compliance time may be adjusted.

(Pratt & Whitney letter PSE:HHB:0-4-6-1-33 dated April 6, 1970, pertains to this subject.)

This amendment is effective December 29, 1970.

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS E2EA](https://openairdocs.org/tcds/E2EA): Pratt & Whitney; names 16 of 16 models: JT8D-17AR, JT8D-1, JT8D-17R, JT8D-15A, JT8D-15, JT8D-17, JT8D-7, JT8D-17A…
- [TCDS E9NE](https://openairdocs.org/tcds/E9NE): Pratt & Whitney; names 5 of 5 models: JT8D-217C, JT8D-217A, JT8D-219, JT8D-209, JT8D-217

## 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: 150 (0 by airframe model, 150 by engine model)
- Makers: Mcdonnell Douglas 106, Boeing 39, Douglas 4, 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-219](https://openairdocs.org/engine/pratt-whitney-jt8d-219): 22 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-217C](https://openairdocs.org/engine/pratt-whitney-jt8d-217c): 2 aircraft (engine model)
- [Pratt & Whitney JT8D-9](https://openairdocs.org/engine/pratt-whitney-jt8d-9): 1 aircraft (engine model)
- [Pratt & Whitney JT8D-15A](https://openairdocs.org/engine/pratt-whitney-jt8d-15a): 1 aircraft (engine model)
- [Pratt & Whitney JT8D-17A](https://openairdocs.org/engine/pratt-whitney-jt8d-17a): 1 aircraft (engine model)

All 12 models: https://openairdocs.org/ad/70-26-05/models.md
Every aircraft: https://openairdocs.org/ad/70-26-05/aircraft.md

Its text cites no advisory circulars or STCs.

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