# AD 66-14-03: Crankshaft Idler Shafts

- Type: Airworthiness directive
- Status: Current
- Products: Lycoming Engines O-540-B2B5
- Effective: July 9, 1966
- Superseded by: Nothing supersedes this AD
- Product type: Engine
- Amendment: 39-248
- Registered aircraft: 5,272 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/ED0A0E28D411C56B8625682A004EBCE7.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/66-14-03

## The airworthiness directive

66-14-03 LYCOMING: Amdt. 39-248, Part 39, Federal Register June 8, 1966. Applies to Model O-540- B2B5 Engines, Serial Numbers 101-40 through 8267-40, Installed in Piper PA-25 and Intermountain Manufacturing Company Airplanes, Except Engines Remanufactured at Lycoming after November 14, 1965. Compliance required as indicated, unless already accomplished. To prevent further failures of crankshaft idler shafts, accomplish the following: (a) For engines with less than 300 hours' time in service on the effective date of this AD since overhaul, comply with (d) before the accumulation of 400 hours' time in service since overhaul. (b) For engines with less than 300 hours' time in service on the effective date of this AD since new that have never been overhauled, comply with (d) before the accumulation of 400 hours' time in service since new. (c) For engines with 300 or more hours' time in service on the effective date of this AD since new or overhaul, comply with (d) within the next 100 hours' time in service. (d) Replace crankshaft idler shaft, P/N 70390, and accessory housing, P/N 71648, with crankshaft idler shaft, P/N 73014, and accessory housing, P/N 75367 or 71648-85. (Lycoming Service Bulletin No. 308 pertains to this subject.) This directive effective July 9, 1966.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS E-295](https://openairdocs.org/tcds/E-295): Lycoming Engines; names 1 of 47 models: O-540-B2B5

## 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: 5,272 (0 by airframe model, 5,272 by engine model)
- Makers: Piper 3,539, Cessna 1,096, Maule 232, Robinson Helicopter 138, Britten-Norman 32, Aero Commander 23, Siai-Marchetti 18, S.O.C.A.T.A. 15, Callair 11, Agusta 10

Models with the most aircraft:

- [Lycoming 0-540 series](https://openairdocs.org/engine/lycoming-0-540-series): 5,228 aircraft (engine model)
- [Lycoming O-540-B2B5](https://openairdocs.org/engine/lycoming-o-540-b2b5): 27 aircraft (engine model)
- [Lycoming O-540 series](https://openairdocs.org/engine/lycoming-o-540-series): 17 aircraft (engine model)

All 3 models: https://openairdocs.org/ad/66-14-03/models.md
Every aircraft: https://openairdocs.org/ad/66-14-03/aircraft.md

Its text cites no advisory circulars or STCs.

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