# STC SA1157NW

- Type: Supplemental type certificate
- Status: Current, Reissued
- Holder: United Airlines Inc, United States
- Description: Removal of the JT9D-3A engine fan case splitter (per United Air Lines COA 8-1464, ER #6) from the Boeing - 100A nacelles (blow-in-door inlets).  FAA Approved Airplane Flight Manual Supplement for the Model 747-122 is required as part of this approval.
- Applied: January 9, 1981
- Status date: November 30, 2011
- Product: Aircraft, Large Multi-Engine
- Certification basis: Part 21, Part 25
- Data sheets: [TCDS A20WE](https://openairdocs.org/tcds/A20WE)
- Certificate PDF: https://openairdocs.org/files/sha256/a9/d4/a9d48355e68bc6309ae7240975202e76509b7756f8bde1a0fe0e7dc4ad787144
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/4AFA3CD8264F071486257992006F9D67.0001
- DRS record last changed: December 5, 2025
- Page: https://openairdocs.org/stc/SA1157NW

## ADs that name it (0)

None.

## Approved models (1)

- The Boeing Company 747-100 Series ([TCDS A20WE](https://openairdocs.org/tcds/A20WE))

## 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 United Air Lines, Inc.

600 Jefferson Street Houston, Texas 77002 Part 25 of the Federal Aviation Regulations.

A20WE

Boeing

747-100 Description of Type Design Change: Removal of the JT9D-3A engine fan case splitter (per United Air Lines COA 8-1464, ER #6) from the Boeing – 100A nacelles (blow-in-door inlets). FAA Approved Airplane Flight Manual Supplement for the Model 747-122 is required as part of this approval.

Limitations and Conditions: The approval of this change in type design applies basically to the above model aircraft only. This approval should not be ex tended to other specific airplanes of this model on which other previously approved modifications ar e incorporated unless it is determined that the interrelationship between this cha nge and any of those other previ ously approved modifications will introduce no adverse effect upon the airworthiness of th e 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. A copy of this Certificate No. SA1157NW shall be maintained as part of the permanent records for the modified aircraft.

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: January 9, 1981

Date of issuance: January 21, 1981

Date reissued: November 30, 2011

( Signature) Haifa Haj-Eid Supervisor, Technical & Administrative Support Staff, Los Angeles Aircraft Certification Office ( 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.**

## Every issue (1)

- November 30, 2011: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/a9/d4/a9d48355e68bc6309ae7240975202e76509b7756f8bde1a0fe0e7dc4ad787144)

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