# STC SA1794NM

- Type: Supplemental type certificate
- Status: Current, Issued
- Holder: Stuart K Mitzel, United States
- Description: Installation of a Pratt and Whitney R-985-14B, a Hamilton Standard 2D30-6101A-12 propeller, a 10 1/2 x 4 tailwheel with heavy duty axle, D & S supply heater and muff, Beech model 18 exhaust stack, a weatherly model 620 carburetor air box and associated parts.
- Applied: January 31, 1983
- Status date: March 3, 1983
- Product: Aircraft, Large Multi-Engine
- Certification basis: Part 21
- Data sheets: [TCDS A-743](https://openairdocs.org/tcds/A-743)
- Certificate PDF: https://openairdocs.org/files/sha256/8f/74/8f74f338d4b24f5ab5969b86fbc9292e5b1d4e10fb9899e6d3b20b6346f43e8c
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/84663CFE6602A936862579DF0071DC0A.0001
- DRS record last changed: December 5, 2025
- Page: https://openairdocs.org/stc/SA1794NM

## ADs that name it (0)

None.

## Approved models (1)

- Boeing Airplane Company Wichita Division B75N1 (Navy N2S-3) ([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 SA1794NM This certificate issued to: Stuart K. Mitzel Turt 42 of the Civil AiX Regulations:

Original Product - Typebertificate Number: A-743 Make: Boeing Model: B75N1 Description of Type Design Change: Installation of a Pratt and Whitney R-985-14B;

a Hamilton Standard 2D30-6101A-12 propeller; a 10½x4 tailwheel with heavy duty axle; D&S supply heater and muff; Beech model 18 exhaust stack; a Weatherly model 620 carburetor air box; and associated parts.

Linium andbandition: Data pertaining to this modification are considered inadequate for duplication in other aircraft. This approval is limited to the installation in Boeing Model B75N1, Serial Number 75-6829 only. A copy of this Certificate and Addendum shall be maintained as part of the permanent records for the modified aircraft.

Date of Application: January 31, 1983 Tate rissed:

I ate ef isuance: March 3, 1983 Date Amended:

FEDERAL AVTATION Tester H.

( Signature ) TOM MISTER OR Acting Manager, Seattle Aircraft Certification Office, ANM-100S (Title)

47.

United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate (Continuation Sheet) March 3, 1983 Number SA1794NM Supplemental Type Certificate ADDENDUM NO. SA1794NM The conditions and limitations of Type Certificate Data Sheet A743 apply except where superseded by the following:

Supplemental Type Certificate Data Sheet, which is part of STC SA1794NM, prescribes the conditions and limitations under which the product for which the STC was issued meets the airworthiness requirements of the Civil Air Regulations:

Supplemental Type Certificate HOLDER: Stuart K. Mitzel BOEING B75N1 (LANDPLANE - NORMAL CATEGORY) AS MODIFIED BY STC SA1794NM Engine: Pratt & Whitney R985-14B Engine Limits: 450 Hp @ 2300 RPM for 5 min.

400 Hp @ 2200 max cont.

Fuel: 80/87 min grade aviation gasoline Propeller: Hamilton Standard 2D30-6101A-12 Propeller Limits: 550 hp @ 2300 RPM max continuous 605 hp @ 2450 RPM takeoff Serial Number Eligible: 75-6829 All else the same as TDS A-743

- END -

**A FORM 8110-2-1 (10-69) PAGE 3 OF 3PAGES C FAA AC 73-2651**

## Every issue (1)

- March 3, 1983: Issued, Current. [certificate](https://openairdocs.org/files/sha256/8f/74/8f74f338d4b24f5ab5969b86fbc9292e5b1d4e10fb9899e6d3b20b6346f43e8c)

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