# STC SA3406WE

- Type: Supplemental type certificate
- Status: Current, Reissued
- Holder: United Aeronautical Corporation, United States
- Description: Modification of the oxygen system including the addition of a supply bottle, pressure relief valve, and a microphone in the smoke masks.
- Applied: April 22, 1977
- Status date: April 15, 2015
- Product: Aircraft, Large Airplane
- Certification basis: Part 21
- Data sheets: [TCDS 6A3](https://openairdocs.org/tcds/6A3)
- Certificate PDF: https://openairdocs.org/files/sha256/5f/9a/5f9a10f3a7448db47f32b51a33d67c8114ce4a433ff1bd06b0e3ef4ef8d463df
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/F26964B117A49D4C86257E2A005FD8EE.0001
- DRS record last changed: December 6, 2025
- Page: https://openairdocs.org/stc/SA3406WE

## ADs that name it (0)

None.

## Approved models (1)

- The Boeing Company Navy R6D-1 ([TCDS 6A3](https://openairdocs.org/tcds/6A3))

## 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.

United States Of America Department of Transportation - Federal Aviation Administration Supplemental Type Certificate This certificate has been reissued to replace the original certificate reported as lost.

This Certificate issued to United Aeronautical Corporation 7360 Laurel Canyon Blvd.

North Hollywood, California 91605 Part 4b of the Civil Air Regulations.

Effective October 1, 1949 and amendment 4b-2 dated August 25, 1955.

6A3 The Boeing Company R6D-1 Serial Number 43690 – One Only

Description of Type Design Change : Modification of the oxygen system including the addition of a supply bottle, pressure relief valve, and a microphone in the smoke masks in accordance with Aero Union Drawing List Number AU8100 dated April 22, 1977, or later sealed revision.

Limitations and Conditions : Data pertaining to this modification are considered inadequate for duplication in other aircraft. This approval is limited to the installation made in Douglas Mo del R6D-1 Serial Number 43690 only.

Date of application : April 22, 1977

Date of issuance : May 19, 1977

Date reissued : April 15, 2015

(Signature) Supervisor, Technical and Administrative Support Staff Los Angeles Aircraft Certification Office (Title)

## Every issue (1)

- April 15, 2015: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/5f/9a/5f9a10f3a7448db47f32b51a33d67c8114ce4a433ff1bd06b0e3ef4ef8d463df)

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