# AD 75-04-04: Oil Line System

- Type: Airworthiness directive
- Status: Current
- Products: Regal Air 305A with STC SA504SW or SA568SW
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Amendment: 39-2203
- Registered aircraft: 195 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/CE92AE1B75BDFA3B86256E01005ADBA9.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/75-04-04

## The airworthiness directive

75-04-04 CESSNA AIRCRAFT CORPORATION: Amendment 39-2067 as amended by Amendment 39-2203. Applies to Cessna Model 305A series airplanes, modified in accordance with STC SA568SW or SA504SW (oil line rerouting), including airplanes listed in Note 3 of Aircraft Specification 5A5.

Compliance required within the next twenty-five hours' time in service after the effective date of this AD, unless already accomplished.

To prevent failure of the aluminum elbow fitting, P/N X34352, remove the fitting from the oil cooler and replace with a fitting of the same part number fabricated from brass, or Weatherhead P/N C5405X10X6, or an equivalent part approved by the Chief, Engineering and Manufacturing Branch, Flight Standards Division, Southwest Region, Federal Aviation Administration, Fort Worth, Texas.

(NOTE: Advisory Circular AC 43.13-1A, Chapter 10, provides information on the proper flex line installation procedure that should be followed when reconnecting the oil system line.These parts are available from Ector Aircraft Company, 414 East Hillmont, Odessa, Texas 79760.)

Amendment 39-2067 became effective March 10, 1975.

This amendment 39-2203 becomes effective upon publication in the Federal Register.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 5A5](https://openairdocs.org/tcds/5A5): Regal Air Inc.; names 1 of 4 models: 305A

## 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: 195 (195 by airframe model, 0 by engine model)
- Makers: Cessna 168, Cessna Ector 20, Cessna Claassen 2, Cessna Allardice 1, Cessna-Macone 1, Cessna-Morse 1, Cessna-Vansant Interprises-Inc 1, Cessna/Whitehouse 1

Models with the most aircraft:

- [Cessna 305A](https://openairdocs.org/model/cessna-305a): 166 aircraft (airframe model)
- [Cessna Ector 305A](https://openairdocs.org/model/cessna-ector-305a): 20 aircraft (airframe model)
- [Cessna 305A (O-1A)](https://openairdocs.org/model/cessna-305a-o-1a): 2 aircraft (airframe model)
- [Cessna Claassen 305A(0-1A)](https://openairdocs.org/model/cessna-claassen-305a-0-1a): 2 aircraft (airframe model)
- [Cessna/Whitehouse 305A](https://openairdocs.org/model/cessna-whitehouse-305a): 1 aircraft (airframe model)
- [Cessna-Macone 305A](https://openairdocs.org/model/cessna-macone-305a): 1 aircraft (airframe model)
- [Cessna Allardice 305A](https://openairdocs.org/model/cessna-allardice-305a): 1 aircraft (airframe model)
- [Cessna-Vansant Interprises-Inc 305A](https://openairdocs.org/model/cessna-vansant-interprises-inc-305a): 1 aircraft (airframe model)
- [Cessna-Morse 305A](https://openairdocs.org/model/cessna-morse-305a): 1 aircraft (airframe model)

All 9 models: https://openairdocs.org/ad/75-04-04/models.md
Every aircraft: https://openairdocs.org/ad/75-04-04/aircraft.md

## Related documents

- [AC 43.13-1B CHG 1 Ed Update](https://openairdocs.org/ac/43.13-1): Acceptable Methods, Techniques, and Practices—Aircraft Inspection and Repair. Cited as AC 43.13-1A in the AD's requirements
- [STC SA504SW](https://openairdocs.org/stc/SA504SW): Rerouting of oil to oil cooler and addition of extra cooler.. Stephen Noyes, Named in the applicability
- [STC SA568SW](https://openairdocs.org/stc/SA568SW): Increase gross weight to 2,300 pounds, oil system mod per Option One Installation Instructions... Air Repair Inc, Named in the applicability

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