# STC SA2491NM

- Type: Supplemental type certificate
- Status: Historical, Surrendered
- Holder: Hollingsead International Inc, United States
- Description: Installation of a dual Litton LTN-211 VLF/Omega navigation system. (707-330C Series, S/N 20124)
- Applied: May 10, 1985
- Status date: March 19, 2009
- Product: Aircraft, Large Airplane
- Certification basis: Part 25
- Data sheets: [TCDS 4A26](https://openairdocs.org/tcds/4A26)
- Certificate PDF: https://openairdocs.org/files/sha256/0a/a9/0aa9057353fc344a282e9778afa48db76054a4e3b304c0da3e1d80f2887b7cef
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/FFDE25660B04D0E7862570D1006A104F.0001
- DRS record last changed: December 5, 2025
- Page: https://openairdocs.org/stc/SA2491NM

## ADs that name it (0)

None.

## Approved models (2)

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

## 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.

Number SA2491NM

This Certificate issued to Hollingsead International 7416 Hollister Avenue Goleta, CA 93117

Part 4b* of the Civil Air Regulations.

*Certification basis is set forth in Type Certificate Data Sheet 4A26 Original Product Type Certificate Number 4A26 Make : Boeing Model : 707-330C Series, Serial Number 20124 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, Serial Number 20124. 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.

This certificate and the supporting data, which is the basis for approval, shall remain in effect until surrendered, suspended, revoked or a termination date is otherwise established by the Administrator of the Federal Aviation Administration.

Date of application : May 10, 1985

Date of issuance : September 11, 1985

Date reissued : August 12, 1991; July 11, 1995;

March 15, 1996; April 1, 1998; August 1, 2005

Date amended

( Signature)

Manager, Technical & Administrative Support Staff, Los Angeles Aircraft Certification Office ( Title)

## Every issue (1)

- March 19, 2009: Surrendered, Historical. [certificate](https://openairdocs.org/files/sha256/0a/a9/0aa9057353fc344a282e9778afa48db76054a4e3b304c0da3e1d80f2887b7cef)

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