# STC SA3912NM

- Type: Supplemental type certificate
- Status: Current, Reissued
- Holder: Northrop Grumman Systems Corporation, United States
- Description: Installation of a Dual Litton LTN-92 Inertial Navigation System
- Applied: December 10, 1987
- Status date: April 12, 2016
- Product: Aircraft, Large Airplane
- Certification basis: Part 21
- Data sheets: [TCDS A3WE](https://openairdocs.org/tcds/A3WE)
- Certificate PDF: https://openairdocs.org/files/sha256/ef/4e/ef4e8ad757a18cf0cd75204a072464ba4adf654ae52f5c7ca081703f86e305d9
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/F95D096DB62D710686257FA200654FDB.0001
- DRS record last changed: December 6, 2025
- Page: https://openairdocs.org/stc/SA3912NM

## ADs that name it (0)

None.

## Approved models (1)

- The Boeing Company 727-200 Series ([TCDS A3WE](https://openairdocs.org/tcds/A3WE))

## 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.

This Certificate issued to Northrop Grumman Systems Corporation 21240 Burbank Blvd.

Woodland Hills, California 91367-6675 Part 4b* of the Civil Air Regulations *(For certification basis see Type Certificate Data Sheet A3WE) Original Product Type Certificate Number :

A3WE The Boeing Company 727-200

Description of Type Design Change: Installation of a Dual Litton LTN-92 Inertial Navigation System in accordance with FAA approved Litton Aero Products Drawing List 454011-10, Revision “A”, dated January 20, 1988, or later FAA approved revision.

Litton Aero Products FAA approved Airplane Flight Manual Supplement No. 464654, Revision “N/C” dated January 22, 1988, or later FAA approved revision is required with this installation.

Limitations and Conditions: This installation should not be incorporated in any aircraft of this model unless STC SA3917SW has been installed. The approval should not be incorporated in any aircraft unless it is determined that the interrelationship between this installation and any previously approved configuration will not introduce any adverse effect upon the airworthiness of the 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 : December 10, 1987

Date of issuance : January 22, 1988

Date reissued : April 12, 2016

(Signature) Supervisor, Technical & Administrative Support Staff (Title)

NOTE:

**DO NOT DELETE THIS PAGE.**

**DO NOT ADD ANY DATA TO THIS PAGE.**

**THIS PAGE IS FOR PAGE NUMBERING PURPOSES, PLEASE DISCARD PRINTED COPY.**

Number (STC No.)

## Every issue (1)

- April 12, 2016: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/ef/4e/ef4e8ad757a18cf0cd75204a072464ba4adf654ae52f5c7ca081703f86e305d9)

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