# STC SA2491NM-D

- Type: Supplemental type certificate
- Status: Historical, Surrendered
- Holder: Hollingsead International, United States
- Description: ONE-ONLY STC:  Installation of a Dual Litton LTN-211 VLF/Omega Navigation System, Serial Number 20124 ONLY.
- Applied: May 10, 1985
- Status date: March 19, 2009
- Product: Aircraft, Large Multi-Engine
- Certification basis: Part 21, Part 21, Part 21, Part 21, Part 21, Part 21
- Data sheets: [TCDS 4A26](https://openairdocs.org/tcds/4A26)
- Certificate PDF: https://openairdocs.org/files/sha256/1f/1e/1f1eaf371f342b5f487ac9bbb1c46b2c26ec1f6e0c2eb05177d3f4784233a921
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/CC05BEE2EF43E17D862575D0005F3A2E.0001
- DRS record last changed: December 5, 2025
- Page: https://openairdocs.org/stc/SA2491NM-D

## ADs that name it (0)

None.

## Approved models (1)

- The Boeing Company 707-300C Series ([TCDS 4A26](https://openairdocs.org/tcds/4A26))

## What the certificate says

This is OCR from the scanned FAA certificate. OCR can misread letters and numbers.

United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate Number: SA2491NM-D This certificate issued to: Hollingsead International Certificate 2226 Goodyear Avenue SURRENDERED Ventura, California 93003 on - 3-19-09 Part Ab* of the Civil Air Regululions. *Certification basis is set forth in Type Certificate Data Sheet 4A26 Original Product Type Certificate Number 4A26 Make: Boeing Model: 707-330C Series, S/N 20124, one only Description of Type Design Change:

Installation of a Dual Litton LTN-211 VLF/Omega Navigation System in accordance with FAA approved Tracor Aviation DRAWING List No. DL-341-001, Revision "A", dated June 24, 1985.

FAA approved Tracor Airplane Flight Manual Supplement No. TA-CH-001, New Issue, FAA approved on September 6, 1985, is required as part of this installation.

Limitations and Conditions: The approval of this change in type design applies only to Boeing 707-330C, S/N 20124.

Date of Application: May 10, 1985 Date Reissued: August 12, 1991; July 11, 1995;

March 15, 1996; April 1, 1998; August 1, 2005 July 31, 2006, May 7, 2007 Date of Issuance: September 11, 1985 Date Amended:

FEDERAL AVIATION By Direction of the Administrator Calt K. Woo (Signature) Manager, Technical & Administrative Support TOMINISTRATO Staff, Los Angeles Aircraft Certification Office (Title)

TRANSFER ENDORSEMENT Transfer the ownership of the Supplemental Type Certificate Number to (Name of transferee) (Address of transfer) (Number and street) (City, State, and Zip code) from (Name of grantor) (Print or type) (Address of grantor) (Number and street) (City, State, and Zip code) Extent of Authority (if licensing agreement):

Signature of grantor (In ink):

## Every issue (2)

- March 19, 2009: Surrendered, Historical. [certificate](https://openairdocs.org/files/sha256/1f/1e/1f1eaf371f342b5f487ac9bbb1c46b2c26ec1f6e0c2eb05177d3f4784233a921)
- July 31, 2006: Reissued, Historical. [certificate](https://openairdocs.org/files/sha256/c1/bc/c1bc70f30d5b078e29f02e86da5eb099a8b28a4ff32ba230b2c2343686b2a101)

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