# STC SA3-672

- Type: Supplemental type certificate
- Status: Current, Reissued
- Holder: D'Shannon Products Ltd., United States
- Description: Installation of Lycoming O-360-A1A, A1D, or B1B engine with McCauley 2D36C14-X/78KM-4 propeller or Lycoming O-360-A1A and A1D engines with Hartzell HC-C2YK-1A/7666A-2 propeller.  Data required:  Doyn Aircraft, Inc. Drawings: 1000, 1005 Rev. C, 1006 Rev. C, 1009, 1010 Rev. A, 1011, 1012 Rev. A, 1013, 1014, 1015, 1016, 1099, 1100 Rev. B, 1101 Rev. A, 1102, 1103 Rev. A, 1104, 1107, 1150.  Drawing Changes Notices: 1005-5A, 1006-8A, 1006-6, 1009-2A, 1199-1A, 1199-2A, and 1199-3A.
- Applied: July 25, 1961
- Status date: July 14, 2011
- Product: Aircraft, Single-Engine
- Certification basis: Part 3, Part 21
- Data sheets: [TCDS A-799](https://openairdocs.org/tcds/A-799)
- Certificate PDF: https://openairdocs.org/files/sha256/95/d2/95d27a634bd382604b87e11c96a29fea8b75205b3ba880ea1cc2fa64dcf53074
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/456B3D2C0788894A862578EF0046EE20.0001
- DRS record last changed: December 6, 2025
- Page: https://openairdocs.org/stc/SA3-672

## ADs that name it (2)

- [AD 82-07-02](https://openairdocs.org/ad/82-07-02): Engine Crankcase Breather · Lycoming O-360-A1A engine and Hartzell HC-C2YK-1B/7666A-2… (Avcon Industries STC SA1324CE or 14 others). Effective Apr 8, 1982. Named in the applicability
- [AD 69-15-03](https://openairdocs.org/ad/69-15-03): Muffler Assembly · Lycoming O-320-A1A, A1B, A3A, A3B or Lycoming O-320-B1A, B1B… (D'Shannon Products STC SA135CE or 8 others). Effective Aug 20, 1969. Named in the applicability

## Approved models (2)

- The Cessna Aircraft Company 170A ([TCDS A-799](https://openairdocs.org/tcds/A-799))
- The Cessna Aircraft Company 170B ([TCDS A-799](https://openairdocs.org/tcds/A-799))

## What the certificate says

Read from the PDF's text layer, without the form's printed wording; the layout is lost and the order can differ. The PDF is the record.

This certificate issued to

Part 3 of the Civil Air Regulations.

Installation of Lycoming O-360-A1A, A1D, or B1B engine with McCauley 2D36C14-X/78KM-4 propeller or Lycoming O-360-A1A and A1D engines with Hartzell HC-C2YK-1A/7666A-2 propeller. Data required: Doyn Aircraft, Inc. Drawings: 1000, 1005 Rev. C, 1006 Rev. C, 1009, 1010 Rev. A, 1011, 1012 Rev. A, 1013, 1014, 1015, 1016, 1099, 1100 Rev. B, 1101 Rev. A, 1102, 1103 Rev. A, 1104, 1107, 1150. Drawing Changes Notices: 1005-5A, 1006-8A, 1006-6, 1009-2A, 1199-1A, 1199-2A, and 1199-3A.

The following FAA Approved Airplane Flight Manual Supplements are required:

1. Dated July 14, 1961, is required for Lycoming O-360-A1A engine and McCauley Prop;

2. Dated June 28, 1963, is required for Lycoming O-360-B1B engine and McCauley Prop;

3. Dated October 20, 1965, is required for Lycoming A1A or A1D engine and McCauley or Hartzell Prop.

Compatibility of this modification with other previously approved modifications must be determined by the installer.

D’Shannon Products, Ltd.

1309 County Road 134 Buffalo, MN 55313 799 Make : Cessna Model : 170A, 170B Date of application :

Date of issuance : July 25, 1961

Date reissued : 6/28/63; 10/20/65; 1/25/66; 5/17/78; 5/12/11;

7/14/11

( Signature) Melvin D. Taylor Manager Atlanta Aircraft Certification Office

( Title)

## Every issue (2)

- July 14, 2011: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/95/d2/95d27a634bd382604b87e11c96a29fea8b75205b3ba880ea1cc2fa64dcf53074)
- May 12, 2011: Reissued, Historical. [certificate](https://openairdocs.org/files/sha256/b4/42/b442c7b0ff170337fd4ac9ae5ef3155080c30910d2d8a125ecc891e18924dde9)

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