# AD 74-09-03: Compressor Rotor Discs

- Type: Airworthiness directive
- Status: Current
- Products: Honeywell International T5309C, T5311A and T5311B
- Effective: May 2, 1974
- Superseded by: Nothing supersedes this AD
- Product type: Engine
- Amendment: 39-1823
- Registered aircraft: 97 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/CD54BFC9847F60D78625682A0056F87D.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/74-09-03

## The airworthiness directive

74-09-03 AVCO LYCOMING: Amendment 39-1823. Applies to all Avco Lycoming T5309C, T5311A and T5311B turboshaft engines. Compliance required, unless already accomplished, prior to the accumulation of 100 hours in service after the effective date of this AD. To prevent possible compressor disc or impeller assembly failures leading to partial or complete loss of engine power, remove and replace the second, third, fourth, and fifth stage compressor rotor discs and centrifugal impeller assemblies in accordance with the table below. COMPONENT - 2nd Stage Compressor Rotor Disc; REMOVE P/N - 1-100-239-01; INSTALL P/N - 1- 100-239-04 or later FAA approved P/N COMPONENT - 3rd Stage Compressor Rotor Disc; REMOVE P/N - 1-100-242-01 or 1-100-242-06; INSTALL P/N - 1-100-242-09 or later FAA approved P/N COMPONENT- 4th Stage Compressor Rotor Disc; REMOVE P/N - 1-100-244-01 or 1-100-244-02; or 1-100-244-04 or 1-100-244-06; INSTALL P/N - 1-100-244-08 or later FAA approved P/N COMPONENT- 5th Stage Compressor Rotor Disc; REMOVE P/N - 1-100-417-01 or 1-100-417-02; INSTALL P/N - 1-100-417-05 or later FAA approved P/N COMPONENT - Centrifugal Impeller Assembly; REMOVE P/N - 1-100-440-04 or 1-100-440-07; INSTALL P/N - 1-100-440-07; Rev. B or later FAA approved P/N Upon submission of substantiating data through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, FAA, New England Region, may adjust the compliance time. NOTE: (Avco Lycoming Service Bulletin Number 0033 pertains to this subject.) This amendment becomes effective May 2, 1974.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS E1EA](https://openairdocs.org/tcds/E1EA): Ozark Aeroworks LLC; names 3 of 5 models: T5311A, T5311B, T5309C

## 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: 97 (0 by airframe model, 97 by engine model)
- Makers: Bell 69, Garlick Helicopters 7, Grumman 4, Southwest Florida 3, Western International Avia 2, Williams Helicopter 2, Anderson Douglas 1, Bell-Colonial 1, Bell-Sw Florida Avn 1, Christen Industries 1

Models with the most aircraft:

- [Lycoming T-53 series](https://openairdocs.org/engine/lycoming-t-53-series): 95 aircraft (engine model)
- [Lycoming T5311B](https://openairdocs.org/engine/lycoming-t5311b): 2 aircraft (engine model)

All 4 models: https://openairdocs.org/ad/74-09-03/models.md
Every aircraft: https://openairdocs.org/ad/74-09-03/aircraft.md

Its text cites no advisory circulars or STCs.

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