# AD 78-12-04: No. 2 Bearing Pressure Oil Transfer Tube Assembly

- Type: Airworthiness directive
- Status: Current
- Products: Pratt & Whitney Canada PT6A-38, PT6A-41 and PT6A-45A
- Effective: June 19, 1978
- Superseded by: Nothing supersedes this AD
- Product type: Engine
- Amendment: 39-3234
- Registered aircraft: 2,347 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/0932E0909FFC58168625682C00588F75.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/78-12-04

## The airworthiness directive

78-12-04 PRATT & WHITNEY AIRCRAFT: Amendment 39-3234. Applies to all Pratt & Whitney Aircraft of Canada, Limited PT6A-38 engines prior to Serial Number PCE-79179, PT6A-41 engines prior to Serial Number PCE-80718, PT6A-45A engines prior to Serial Number PCE-84108 and Pratt & Whitney Aircraft PT6A-38 engines prior to Serial Number P-79179 with Part Number 3019268 or 3027054 No. 2 bearing pressure oil transfer tube assemblies.

Compliance required within the next 50 hours in service, after the effective date of this AD, unless already accomplished.

To preclude oil leakage from the No. 2 bearing pressure oil transfer tube assembly replace the Part Number 3019268 and 3027054 tube assemblies with Part Number 3030150 tube assembly in accordance with Paragraph 2, accomplishment instructions in Pratt & Whitney Aircraft of Canada, Limited Service Bulletin No. 3099 or approved equivalent parts.

Aircraft may be flown to a base for performance of maintenance required by this ADper FAR 21.197 or FAR 21.199.

All equivalent parts must be approved by the Chief, Engineering and Manufacturing Branch of the Eastern Region of the FAA.

This amendment is effective June 19, 1978.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS E4EA](https://openairdocs.org/tcds/E4EA): Pratt & Whitney Canada Corp.; names 3 of 54 models: PT6A-38, PT6A-41, PT6A-45A

## 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: 2,347 (0 by airframe model, 2,347 by engine model)
- Makers: Beech 578, Cessna 435, Air Tractor 393, Raytheon 240, Piper 228, Pilatus 110, Socata 92, Dehavilland 57, Ayres 45, Epic 20

Models with the most aircraft:

- [Pratt & Whitney PT6A series](https://openairdocs.org/engine/pratt-whitney-pt6a-series): 2,217 aircraft (engine model)
- [Pratt & Whitney PT6 series](https://openairdocs.org/engine/pratt-whitney-pt6-series): 43 aircraft (engine model)
- [Pratt & Whitney Canada PT6A-41](https://openairdocs.org/engine/pratt-whitney-canada-pt6a-41): 42 aircraft (engine model)
- [U/A Canada PT6A-41](https://openairdocs.org/engine/u-a-canada-pt6a-41): 42 aircraft (engine model)
- [Pratt & Whitney Canada PT6 series](https://openairdocs.org/engine/pratt-whitney-canada-pt6-series): 3 aircraft (engine model)

All 6 models: https://openairdocs.org/ad/78-12-04/models.md
Every aircraft: https://openairdocs.org/ad/78-12-04/aircraft.md

Its text cites no advisory circulars or STCs.

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