# STC SA1688NM

- Type: Supplemental type certificate
- Status: Current, Issued
- Holder: Valley Investments Promotions, United States
- Description: Installation of a modified BT-13 engine mount
- Applied: August 24, 1982
- Status date: April 8, 1983
- Product: Aircraft, Small Airplane
- Certification basis: Part 21
- Data sheets: [TCDS A-743](https://openairdocs.org/tcds/A-743)
- Certificate PDF: https://openairdocs.org/files/sha256/58/3c/583c24540c5d130b1ba49424108d3d302783720afcc8f32cbcab03abf8c1d75f
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/8622B91F4DCD3654862579FE00713F0E.0001
- DRS record last changed: December 6, 2025
- Page: https://openairdocs.org/stc/SA1688NM

## ADs that name it (0)

None.

## Approved models (1)

- Boeing Airplane Company Wichita Division 75 (Army PT-13) ([TCDS A-743](https://openairdocs.org/tcds/A-743))

## 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 SA 1688N This certificate issued to: Valley Investments Promotions Part 4a ofthe Civi1 Air Regulations:

Original Product Type bertificate Number: A-743 Make: Boeing Model: 75 (Stearman) Description of Type Design Change: Installation of a modified BI-13 engine mount in accordance with Alan W. DeBoer photographs l through 5.

Limitations and Conditions: Data pertaining to this modification are considered inadequate for duplication in other aircraft. This approval is limited to the installation in Boeing, Model 75 (Stearman), Serial Number 754556 only. A copy of this Certificate must be maintained as part of the permanent records for the modified aircraft.

Date of Application: August 24, 1982 Date Reissued:

Date of Issuance: April 8, 1983 Date Amended:

FEDERAL AVIATION By Direction of the Administrator ( Signature ) TOMINIST RAIDS Manager, Seattle Area Aircraft Certification Office, ANM-100S (Title)

**FAA FORM B110-2 (10-68)**

## Every issue (1)

- April 8, 1983: Issued, Current. [certificate](https://openairdocs.org/files/sha256/58/3c/583c24540c5d130b1ba49424108d3d302783720afcc8f32cbcab03abf8c1d75f)

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