# STC SA1640SW

- Type: Supplemental type certificate
- Status: Current, Reissued
- Holder: Century Flight Systems Inc, United States
- Description: Installation of Mitchell automatic flight system AK422/FD consisting of Century IV autopilot/flight director with command electric trim.
- Applied: March 27, 1973
- Status date: July 16, 1984
- Product: Aircraft, Small Multi-Engine
- Certification basis: Part 21
- Data sheets: [TCDS 3A20](https://openairdocs.org/tcds/3A20)
- Certificate PDF: https://openairdocs.org/files/sha256/b7/84/b78458ff6dd4a5facbb9597b506ffeff992915510809c32a33042c876881b9a1
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/5E063694F8285FD985256CC1008214E1.0001
- DRS record last changed: December 5, 2025
- Page: https://openairdocs.org/stc/SA1640SW

## ADs that name it (0)

None.

## Approved models (3)

- Beechcraft Corporation B90 ([TCDS 3A20](https://openairdocs.org/tcds/3A20))
- Beechcraft Corporation C90 ([TCDS 3A20](https://openairdocs.org/tcds/3A20))
- Beechcraft Corporation E90 ([TCDS 3A20](https://openairdocs.org/tcds/3A20))

## 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.

Department of "Cransportation —Jftdtral atriation administration Supplemental t:yje Certificate SA16AOSW Century Flight Systems, Inc.

P.M. 1195 P. 0. Box 610 Mineral Wells, TX 76067 Jfod'yfwdt&fa^fw£feJ:cittM>vn&fwv^ ^ Civil Air 3A20 Beech B-90, C-90, E-90 _ __ 7 . .f . _._ . ._„ Installation of Mitchell Automatic Flight System Model AK422/FD consisting of Century IV Autopilot/Flight Director with Command Electric Trim according to Bulletin No. 546, Revision (6), dated 5-29-74, and Master Drawing List 87A657 Revision E dated 5-29-74.

The following FAA Approved Airplane Flight Manual Supplements are required.

1. Supplement dated April 19, 1973, for AK422 installed in Models B-90 and C-90.

2. Supplement dated April 13, 1973, for AK422/FD installed in Models B-9Q and C-90.

3. Supplement dated April 19, 1973, for AK422 installed in Model E-9'0.

4. Supplement dated April 12, 1973, for AK422/FD installed in Model E-90.

JSaE|bJi£S$e$hte ^MiSSS/"11 °ther Piously approved modifications >JA^*&}&/ifja&<JiTi£t-£hrjlaf>Si4ff/t.na<j£a£a arisen i& £^^t^^fiff-^i^Mi-va/AA4f///rf,rnaf'ti^nf^fef/jffi/i/^jf'- *y March 27, 1973 April 19 , 1973 October 15, 1974, July 16, 1984, Revision 2 ^- allt,,u/rf/.

Don P. Watson Manager, Aircraft Certification Division Southwest Region (Tille)

T/III fi'tificalt may be tiaiujtritd in accordance ualfi hAK 21.17

INSTRUCTIONS: T he Transfer endorsement below may he used to notify the appropriate FAA Regional Office of (he iranjfer of ihii Supplemental Type Certificate.

The FAA will reissue the certificate in the name of ihe transferee and forward it to him.

TRANSFER ENDORSEMENT Transfer the ownership of Supplemental Type Certificate Number to (Name of transferee) (Address of transferee) umber and ilrtrl) , Stair, a from (Name of grantor) (Print or type) .

(Address of grantor) ' and llittl) (City, Stall, and Z.IP cade> Extent of Authority (if licensing agreement):

Signature of grantor (In ink):

**C FAA AC 69-SS36**

## Every issue (1)

- July 16, 1984: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/b7/84/b78458ff6dd4a5facbb9597b506ffeff992915510809c32a33042c876881b9a1)

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