# STC SA637NW

- Type: Supplemental type certificate
- Status: Current, Reissued
- Holder: Franklin Aircraft Engines Inc., United States
- Description: Installation of oil filter kit
- Applied: March 13, 1978
- Status date: May 25, 2022
- Product: Aircraft, Small Airplane
- Certification basis: Part 3, Part 21, Part 33
- Data sheets: [TCDS 3A23](https://openairdocs.org/tcds/3A23), [TCDS 3A12](https://openairdocs.org/tcds/3A12), [TCDS 3A17](https://openairdocs.org/tcds/3A17), [TCDS A-799](https://openairdocs.org/tcds/A-799), [TCDS A-767](https://openairdocs.org/tcds/A-767)
- Certificate PDF: https://openairdocs.org/files/sha256/59/fa/59faf9b1da85cbaba84306617410d0928083fea1226be0fe56b9784d52145c59
- Approved model list and other attachments: [SA637NW_AML.pdf](https://openairdocs.org/files/sha256/57/1a/571a727ca9224b599ea0f38a7c1b6e265bce8adfad77ef20f20015f5a16ca49a)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/1D1438F2D0D9D220862588630055CB2A.0001
- DRS record last changed: December 6, 2025
- Page: https://openairdocs.org/stc/SA637NW

## ADs that name it (0)

None.

## Approved models (28)

- Maule Aerospace Technology Inc. M-4-180C ([TCDS 3A23](https://openairdocs.org/tcds/3A23))
- Maule Aerospace Technology Inc. M-4-180S ([TCDS 3A23](https://openairdocs.org/tcds/3A23))
- Maule Aerospace Technology Inc. M-4-180T ([TCDS 3A23](https://openairdocs.org/tcds/3A23))
- Maule Aerospace Technology Inc. M-4-220 ([TCDS 3A23](https://openairdocs.org/tcds/3A23))
- Maule Aerospace Technology Inc. M-4-220C ([TCDS 3A23](https://openairdocs.org/tcds/3A23))
- Maule Aerospace Technology Inc. M-4-220S ([TCDS 3A23](https://openairdocs.org/tcds/3A23))
- Maule Aerospace Technology Inc. M-4-220T ([TCDS 3A23](https://openairdocs.org/tcds/3A23))
- Maule Aerospace Technology Inc. M-5-220C ([TCDS 3A23](https://openairdocs.org/tcds/3A23))
- Textron Aviation Inc. 170B ([TCDS A-799](https://openairdocs.org/tcds/A-799))
- Textron Aviation Inc. 172B ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- Textron Aviation Inc. 172C ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- Textron Aviation Inc. 172D ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- Textron Aviation Inc. 172E ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- Textron Aviation Inc. 172F (USAF T-41A) ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- Textron Aviation Inc. 172G ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- Textron Aviation Inc. 172H (USAF T-41A) ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- Textron Aviation Inc. 172I ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- Textron Aviation Inc. 172K ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- Textron Aviation Inc. 172L ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- Textron Aviation Inc. 172M ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- Textron Aviation Inc. 175 ([TCDS 3A17](https://openairdocs.org/tcds/3A17))
- Textron Aviation Inc. 175A ([TCDS 3A17](https://openairdocs.org/tcds/3A17))
- Textron Aviation Inc. 175B ([TCDS 3A17](https://openairdocs.org/tcds/3A17))
- Textron Aviation Inc. 175C ([TCDS 3A17](https://openairdocs.org/tcds/3A17))
- Univair Aircraft Corporation 108 ([TCDS A-767](https://openairdocs.org/tcds/A-767))
- Univair Aircraft Corporation 108-1 ([TCDS A-767](https://openairdocs.org/tcds/A-767))
- Univair Aircraft Corporation 108-2 ([TCDS A-767](https://openairdocs.org/tcds/A-767))
- Univair Aircraft Corporation 108-3 ([TCDS A-767](https://openairdocs.org/tcds/A-767))

## 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.

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Original Product 7\SH&HUWLILFDWH1XPEHU Make:

SA637NW Franklin Aircraft Engines, Inc.

136 Racquette Drive Fort Collins, CO 80524 Part 33 Federal Aviation Regulations See attached FAA AML SA637NW, for list of approved models and applicable AW regulations.

Installation of oil filter assembly. See attached FAA Aircraft Model List (AML) No. SA637NW for aircraft makes, models and required data.

1. Data pertaining to this modification are considered inadequate for duplication in other aircraft.

2. Compatibility of this design change with previously approved modifications must be determined by the installer.

March 13, 1978 2/26/1993, 3/31/1993, 4/27/1995, 5/25/2022 July 13, 1978 April 8, 1984 Tina Miller Manager, Program Managment Section Wichita ACO Branch (AIR-7K5) 2

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Date oI transfer:

SA637NW 2

### SA637NW_AML.pdf

**FAA APPROVED MODEL LIST (AML) NO. SA637NW**

Franklin Aircraft Engines, Inc.

Installation of AC or Champion Oil Filter

Page 1 of 1

Item Aircraft Make Aircraft Model TCDS Cert Basis / Amendment AFMS Revision / FAA Approved Date Drawing List Revision* / FAA Approved Date Initial Approval Date Amendment Date 1 Textron Aviation (Cessna) 170B A-797 CAR 3 (dated 11/1/49), as Amended by Amdt 3-1 and 3-2 N/A No. 20751 or Report No. OF-100 7/13/1978 N/A 2 Textron Aviation (Cessna) 172B, 172C, 172D, 172E, 172F, 172G, 172H, 172I, 172K, 172L, 172M 3A12 CAR 3 (dated 11/1/49), as Amended by Amdt 3-1 and 3-2 N/A No. 20751 or Report No. OF-100 7/13/1978 N/A 3 Textron Aviation (Cessna) 175, 175A, 175B, 175C 3A17 CA R 3 (dated 5/15/56) N/A No. 20751 or Report No. OF-100 7/13/1978 N/A 4 UNIVAIR (Stinson) 108, 108-1, 108-2, 108-3 A-767 CAR 3 (dated 11/13/45) N/A No. 20751 or Report No. OF-100 N/A 4/10/1984 5 MAULE M-4-180C, 180T, 180S, M-4-220, -220C, -220S, -220T, M-5-220 3A23 CAR 3 (dated 5/15/56) N/A No. 20751 or Report No. OF-100 N/A 3/22/1988 *Or later FAA Approved revision

FAA Approved:

Tina Miller Manager, Program Management Section Wichita ACO Branch (AIR-7K5)

Date Reissued: 3/31/1993, 5/25/2022

## Every issue (2)

- May 25, 2022: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/59/fa/59faf9b1da85cbaba84306617410d0928083fea1226be0fe56b9784d52145c59), [SA637NW_AML.pdf](https://openairdocs.org/files/sha256/57/1a/571a727ca9224b599ea0f38a7c1b6e265bce8adfad77ef20f20015f5a16ca49a)
- April 27, 1995: Reissued, Historical. [certificate](https://openairdocs.org/files/sha256/78/48/7848e8bac345c7faa345307f5f9bee569a708e73b7251f7cc6e49b2fd355ed44)

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