# AD T83-03-51: Fourth Stage Turbine Rotors Assembly

- Type: Airworthiness directive
- Status: Current
- Products: Honeywell International ALF502L, ALF502L-2, ALF502L-2A, ALF502L-2C, ALF502L-3, ALF502R-3, ALF502R-3A, ALF502R-4, ALF502R-5 and ALF502R-6
- Superseded by: Nothing supersedes this AD
- Product type: Engine
- Registered aircraft: 43 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/37F1EC7BE67A0D2586256862005F1F02.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/T83-03-51

## The airworthiness directive

T83-03-51 AVCO LYCOMING: Telegram issued February 4, 1983. Applies to Avco Lycoming ALF502 series model turbofan engines.

Unless already accomplished for all engines having less than 100 hours total operating time, within the next 10 engine operating hours, remove all fourth stage turbine rotors assembly P/N 2-141-170-23 or -27 and replace with a rotor which has satisfactorily met the etch inspection requirements for the blades per Avco Lycoming Service Bulletin ALF502-72-0038.

NOTE: Avco Lycoming will provide replacement fourth stage turbine rotors which have been etch inspected per Service Bulletin ALF502-72-0038.

Airplanes may be ferried in accordance with the provisions of FAR 21.197 to a base where the AD can be accomplished.

Upon request of an operator an equivalent means of compliance with the requirements of this AD may be approved by the Manager, Engine Certification Branch, FAA, New England Region.

This airworthiness directive becomes effectiveupon receipt.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS E6NE](https://openairdocs.org/tcds/E6NE): CFS Aeroproducts Inc.; names 10 of 12 models: ALF502L-2C, ALF502R-6, ALF502L-2A, ALF502L-3, ALF502R-3, ALF502R-5, ALF502R-3A, ALF502R-4…

## 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: 43 (0 by airframe model, 43 by engine model)
- Makers: Canadair 33, British Aerospace 10

Models with the most aircraft:

- [Lycoming ALF-502 SER. series](https://openairdocs.org/engine/lycoming-alf-502-ser-series): 25 aircraft (engine model)
- [Honeywell ALF-502 series](https://openairdocs.org/engine/honeywell-alf-502-series): 4 aircraft (engine model)
- [Lycoming ALF502L](https://openairdocs.org/engine/lycoming-alf502l): 4 aircraft (engine model)
- [Lycoming ALF502R-5](https://openairdocs.org/engine/lycoming-alf502r-5): 4 aircraft (engine model)
- [Honeywell ALF502R-5](https://openairdocs.org/engine/honeywell-alf502r-5): 2 aircraft (engine model)
- [Lycoming ALF502L-2C](https://openairdocs.org/engine/lycoming-alf502l-2c): 2 aircraft (engine model)
- [Alliedsign ALF502L-2C](https://openairdocs.org/engine/alliedsign-alf502l-2c): 1 aircraft (engine model)
- [Lycoming ALF502L-2](https://openairdocs.org/engine/lycoming-alf502l-2): 1 aircraft (engine model)

All 8 models: https://openairdocs.org/ad/T83-03-51/models.md
Every aircraft: https://openairdocs.org/ad/T83-03-51/aircraft.md

Its text cites no advisory circulars or STCs.

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