# AD 78-12-08: Oil Pump Body

- Type: Airworthiness directive
- Status: Current
- Products: Lycoming Engines O-320-H1AD, O-320-H1BD, O-320-H2AD, O-320-H2BD, O-320-H3AD and O-320-H3BD
- Effective: June 20, 1978
- Superseded by: Nothing supersedes this AD
- Product type: Engine
- Amendment: 39-3239
- Registered aircraft: 27,398 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/F785DF6504949B958625682B0049FBA2.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/78-12-08

## The airworthiness directive

78-12-08 AVCO LYCOMING: Amendment 39-3239. Applies to O-320-H series engines Serial Numbers L-101-76 through L-3829-76, L-3831-76, L-3843-76 through L-3859-76, L-3864-76, L-3866-76, L-3871-76, L-3902-76 through L-3907-76 and all O-320-H series engines overhauled (Remanufactured by Lycoming) before March 24, 1978. Compliance required within the next 10 hours in service, unless already accomplished. a. To prevent oil pump failures, remove, inspect and alter the oil pump body and replace the oil pump driving impeller with driving impeller P/N LW-15998 and the oil pump driven impeller with driven impeller P/N LW-15999 in accordance with AVCO Lycoming Service Bulletin No. 423 dated March 24, 1978, or FAA approved equivalent. b. Equivalent method of compliance must be approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region. This amendment is effective June 20, 1978.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS E-274](https://openairdocs.org/tcds/E-274): Lycoming Engines; names 6 of 60 models: O-320-H3BD, O-320-H2BD, O-320-H2AD, O-320-H3AD, O-320-H1BD, O-320-H1AD

## 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: 27,398 (0 by airframe model, 27,398 by engine model)
- Makers: Piper 11,632, Cessna 9,982, Grumman American Avn. 605, Bellanca 588, Beech 398, Champion 295, Robinson Helicopter 289, American Champion 250, American 116, Gulfstream American 95

Models with the most aircraft:

- [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series): 27,057 aircraft (engine model)
- [Lycoming O-320 series](https://openairdocs.org/engine/lycoming-o-320-series): 256 aircraft (engine model)
- [Lycoming O-320-H2AD](https://openairdocs.org/engine/lycoming-o-320-h2ad): 83 aircraft (engine model)
- [Aerotec O-320 series](https://openairdocs.org/engine/aerotec-o-320-series): 2 aircraft (engine model)

All 4 models: https://openairdocs.org/ad/78-12-08/models.md
Every aircraft: https://openairdocs.org/ad/78-12-08/aircraft.md

Its text cites no advisory circulars or STCs.

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