# AD 74-18-12: Fuel Control Orifice Assembly

- Type: Airworthiness directive
- Status: Current
- Products: Honeywell International TFE731-2
- Effective: September 3, 1974
- Superseded by: Nothing supersedes this AD
- Product type: Engine
- Amendment: 39-1941
- Registered aircraft: 1,026 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/71D74E59654A0755862568550057B14D.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/74-18-12

## The airworthiness directive

74-18-12 AIRESEARCH MANUFACTURING COMPANY of ARIZONA: Amendment 39-1941. Applies to AiResearch Model TFE 731-2-2B engines installed in, but not limited to Lear-Gates Learjet model 35/36 Aircraft, certificated in all categories.

      (A) Before further flight, unless previously accomplished, and prior to the installation of replacement fuel control assemblies, replace the hydromechanical fuel control orifice assembly in accordance with AiResearch Alert Service Bulletin TFE 731-A73-3006, dated August 12, 1974, or later FAA approved revisions.

      (B) Equivalent procedures may be approved by the Chief, Aircraft Engineering Division, FAA Western Region, upon submission of adequate substantiation data.

      (C) Aircraft may be flown to a base for performance of maintenance required by this AD per FAR's 21.197 and 21.199.

This amendment is effective September 3, 1974, for all persons except those to whom it was made effective immediately by telegram dated August 5, 1974.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS E6WE](https://openairdocs.org/tcds/E6WE): Honeywell Aerospace US LLC; names 1 of 23 models: TFE731-2

## 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: 1,026 (0 by airframe model, 1,026 by engine model)
- Makers: Dassault-Breguet 174, Raytheon 152, Cessna 139, Learjet 138, Gates Learjet 119, Dassault 89, Israel Aircraft Industries 80, British Aerospace 48, Raytheon Corporate Jets 27, Gates Lear Jet 24

Models with the most aircraft:

- [Garrett TFE731 series](https://openairdocs.org/engine/garrett-tfe731-series): 694 aircraft (engine model)
- [Honeywell TFE-731-SER series](https://openairdocs.org/engine/honeywell-tfe-731-ser-series): 291 aircraft (engine model)
- [Alliedsign TFE731 series](https://openairdocs.org/engine/alliedsign-tfe731-series): 17 aircraft (engine model)
- [Honeywell TFE731-2](https://openairdocs.org/engine/honeywell-tfe731-2): 10 aircraft (engine model)
- [Honeywell TFE-731 series](https://openairdocs.org/engine/honeywell-tfe-731-series): 8 aircraft (engine model)
- [Alliedsign TFE731-2](https://openairdocs.org/engine/alliedsign-tfe731-2): 3 aircraft (engine model)
- [Garrett TFE731-2](https://openairdocs.org/engine/garrett-tfe731-2): 3 aircraft (engine model)

All 7 models: https://openairdocs.org/ad/74-18-12/models.md
Every aircraft: https://openairdocs.org/ad/74-18-12/aircraft.md

Its text cites no advisory circulars or STCs.

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