# AD 71-11-02: Intake and Exhaust Hydraulic Tappet Plunger Assembly

- Type: Airworthiness directive
- Status: Current
- Products: Lycoming Engines IO-360-A1A, IO-360-A1B, IO-360-A1B6, IO-360-A1C, IO-360-A1D6, IO-360-A2A, IO-360-A2B, IO-360-A2C, IO-360-C1A, IO-360-C1B, IO-360-C1C and IO-360-C1D6
- Effective: March 14, 1972
- Superseded by: Nothing supersedes this AD
- Product type: Engine
- Amendment: 39-1403
- Registered aircraft: 7,047 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/C462620AA0A89FFD86256E01005AD3CA.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/71-11-02

## The airworthiness directive

71-11-02 AVCO LYCOMING: Amdt. 39-1208 as amended by Amendment 39-1403. Applies to all IO- 360A and -C Series engines with serial numbers 1734-51A through 4412-51A and all such series engines remanufactured between 1 September 1965 and 11 October 1967. Compliance required as indicated, unless already accomplished. To prevent valve failures replace the intake and exhaust hydraulic tappet plunger assembly P/N 76290 with P/N 78290 at the time in service specified below: (a) Engines with less than 400 hours in service on P/N 76290 as of the effective date of this AD, shall comply prior to the accumulation of 450 hours in service. (b) Engines with 400 or more hours in service on P/N 76290 as of the effective date of this AD shall comply within the next 50 hours in service. (Note: Lycoming Service Bulletin No. 328 covers this subject.) Amendment 39-1208 was effective May 19, 1971. This Amendment 39-1403 is effective March 14, 1972.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 1E10](https://openairdocs.org/tcds/1E10): Lycoming Engines; names 12 of 89 models: IO-360-C1D6, IO-360-A2A, IO-360-A1C, IO-360-A2B, IO-360-C1B, IO-360-A1A, IO-360-A2C, IO-360-A1B…

## 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: 7,047 (0 by airframe model, 7,047 by engine model)
- Makers: Piper 2,098, Mooney 1,888, Cessna 720, Beech 446, Aviat 188, Diamond Aircraft Ind 175, Rockwell International 129, Aero Commander 74, Lake 57, Aerotek 46

Models with the most aircraft:

- [Lycoming I0360 series](https://openairdocs.org/engine/lycoming-i0360-series): 6,174 aircraft (engine model)
- [Lycoming IO-360 series](https://openairdocs.org/engine/lycoming-io-360-series): 217 aircraft (engine model)
- [Lycoming IO-360-A1A](https://openairdocs.org/engine/lycoming-io-360-a1a): 196 aircraft (engine model)
- [Lycoming IO-360-A1D6](https://openairdocs.org/engine/lycoming-io-360-a1d6): 192 aircraft (engine model)
- [Lycoming IO-360-A1B6](https://openairdocs.org/engine/lycoming-io-360-a1b6): 141 aircraft (engine model)
- [Lycoming IO-360-A1B](https://openairdocs.org/engine/lycoming-io-360-a1b): 52 aircraft (engine model)
- [Lycoming IO-360-C1C](https://openairdocs.org/engine/lycoming-io-360-c1c): 45 aircraft (engine model)
- [Lycoming IO-360-C1D6](https://openairdocs.org/engine/lycoming-io-360-c1d6): 14 aircraft (engine model)
- [Lycoming I0-360 series](https://openairdocs.org/engine/lycoming-i0-360-series): 7 aircraft (engine model)
- [Lycoming IO-360-C1A](https://openairdocs.org/engine/lycoming-io-360-c1a): 7 aircraft (engine model)
- [Lycoming IO-360-A2B](https://openairdocs.org/engine/lycoming-io-360-a2b): 2 aircraft (engine model)

All 11 models: https://openairdocs.org/ad/71-11-02/models.md
Every aircraft: https://openairdocs.org/ad/71-11-02/aircraft.md

Its text cites no advisory circulars or STCs.

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