# AD 79-20-03: Fuel Control, Fuel Pump And Oil Pump Drive Gears

- Type: Airworthiness directive
- Status: Current
- Products: Honeywell International LTP 101-600, LTP 101-600A, LTP 101-600A-1A, LTS101-600A, LTS101-600A-2, LTS101-600B, LTS101-650A-2 and LTS101-650B-1A
- Effective: September 26, 1979
- Superseded by: Nothing supersedes this AD
- Product type: Engine
- Amendment: 39-3567
- Registered aircraft: 34 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/DDA2E4C9FD8E844A8625682B005FA47F.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/79-20-03

## The airworthiness directive

79-20-03 AVCO LYCOMING DIVISION: Amendment 39-3567. Applies to LTS101-600A, -600B, -600A-2, -650A-2, and -650B-1A turboshaft and LTP101-600, -600A, and -600A-1A turboprop engines.

Compliance required prior to further flight, unless already accomplished.

To prevent failure of the fuel control and fuel pump and oil pump drive gears accomplish the following:

1. LTS101 turboshaft model engines:

Remove from service engine fuel control and fuel pump and oil pump and oil pump accessory drive gears, both P/N 4-081-080-04, and replace with gears, both P/N 4-081-080-05. Avco Lycoming Division Alert Notice, 3V-W733, dated July 31, 1979, refers to this subject.

2. LTP101 turboprop model engines:

a. Remove from service engine fuel control and fuel pump accessory drive gears, P/N 4-083-020-01, and replace with P/N 4-083-020-02 gear.

b. Remove from service engine oil pump accessory drive gear, P/N 4-081-080-02, and replace with P/N 4-081-080-06 gear.

NOTE: Issuance of special flight permits in accordance with FAR Part 21.197, not to exceed 2 additional hours in service, is authorized.

The manufacturer's Alert Notice 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 this document from the manufacturer may obtain copies upon request to Customer Service Department, Avco Lycoming Division, 550 South Main Street, Stratford, Connecticut 06514. This document may also be examined at Federal Aviation Administration, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803, and FAA Headquarters, 800 Independence Avenue, S.W., Washington, D.C. 20591.

This amendment becomes effective on September 26, 1979.

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS E7NE](https://openairdocs.org/tcds/E7NE): Intermountain Turbine Services Inc.; names 3 of 4 models: LTP 101-600A, LTP 101-600A-1A, LTP 101-600
- [TCDS E5NE](https://openairdocs.org/tcds/E5NE): Intermountain Turbine Services Inc.; names 2 of 13 models: LTS101-600A-2, LTS101-650B-1A

## 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: 34 (0 by airframe model, 34 by engine model)
- Makers: Bell 12, Messerschmitt-Bolkow-Blohm 9, MBB 3, Messerschmitt 3, Aerospatiale 2, Eurocopter Deutschland 2, Air Tractor 1, Cessna 1, S N I A S 1

Models with the most aircraft:

- [Lycoming LTS-101 series](https://openairdocs.org/engine/lycoming-lts-101-series): 29 aircraft (engine model)
- [Lycoming LTS-101 600A series](https://openairdocs.org/engine/lycoming-lts-101-600a-series): 3 aircraft (engine model)
- [Lycoming LTP-101-600](https://openairdocs.org/engine/lycoming-ltp-101-600): 1 aircraft (engine model)
- [Lycoming LTP101-600A](https://openairdocs.org/engine/lycoming-ltp101-600a): 1 aircraft (engine model)

All 4 models: https://openairdocs.org/ad/79-20-03/models.md
Every aircraft: https://openairdocs.org/ad/79-20-03/aircraft.md

Its text cites no advisory circulars or STCs.

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