# STC SA4946NM

- Type: Supplemental type certificate
- Status: Current, Reissued
- Holder: Aviation Technical Services, United States
- Description: Installation of passenger Service Unit Assemblies modified to include 22 minute duration oxygen generators at all locations except the seat row immediately aft of station 740.0. Approved for model 757-223.
- Applied: May 1, 1990
- Status date: October 24, 2018
- Product: Aircraft, Large Multi-Engine
- Certification basis: Part 21, Part 25
- Data sheets: [TCDS A2NM](https://openairdocs.org/tcds/A2NM)
- Certificate PDF: https://openairdocs.org/files/sha256/53/26/5326c598b66003d0545095320a2bce1459a98c24a8a77976ad27e6b827c0a465
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/1BC94F3FAFB0FC6186258335004C082F.0001
- DRS record last changed: December 6, 2025
- Page: https://openairdocs.org/stc/SA4946NM

## ADs that name it (0)

None.

## Approved models (1)

- The Boeing Company 757-200 ([TCDS A2NM](https://openairdocs.org/tcds/A2NM))

## 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.

Un ited S tates of Am erica Department of Transportation - Federal Aviation Administration Supplemental Type Certificate

Number SA4946NM

This certificate, issued to Aviation Technical Services 3121 109th Street SW Everett, WA 98204-3500

Part 25 of the Federal Aviation Regulations.

Original ProductType Certificate Number: A2NM Make: Boeing Model: 757-223

Description of the Type Design Change: Installation of passenger Service Unit Assemblies modified to include 22 minute duration oxygen generators at all locations except the seat row immediately aft of station 740.0 in accordance with TRAMCO Top Drawing 90-005 Revision B, dated June 21, 1990.

Limitations and Conditions: The approval of this change in type design applies to the aircraft model 757-223 only and should not be extended to other aircraft of this model on which other previously approved modifications are incorporated unless it is determined that the interrelationship between this change and any of those other previously approved modifications will introduce no adverse effect upon the airworthiness of that aircraft. A copy of this Certificate must be maintained as part of the permanent records for the modified aircraft.

If the holder agrees to permit another person to use this certificate to alter the product, the holder shall give the other person written evidence of that permission.

Date of application: May 1, 1990 Date reissued: April 12, 2002; October 24, 2018 Date of issuance: July 9, 1990 Date amended:

FAA FORM 8110-2 (5/14) PAGE 1 OF 2 PAGES By direction of the Administrator

(Signature)

Manager, Seattle ACO Branch (Title)

## Every issue (2)

- October 24, 2018: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/53/26/5326c598b66003d0545095320a2bce1459a98c24a8a77976ad27e6b827c0a465)
- April 12, 2002: Reissued, Historical. [certificate](https://openairdocs.org/files/sha256/bf/4c/bf4c7d1943f1154250049a70d1b91c422551ea9b98d762213cd30161ec1e9a4c)

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