# STC SA941NW

- Type: Supplemental type certificate
- Status: Current, Issued
- Holder: Portable Rock Production, United States
- Description: Installation of a Pratt and Whitney R985-AN-5 engine with a Hamilton Standard 2D30/6101A-12 propeller, Servair type oil tank, modified air filter and minor tubing changes
- Applied: May 7, 1980
- Status date: May 19, 1980
- 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/dc/d4/dcd4c8e0ffe48f2913f52114d27c420d28e5fc05e313d30d01d2ebd1a32db333
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/690AA18EB9CCCEBF86257A3F005793EC.0001
- DRS record last changed: December 6, 2025
- Page: https://openairdocs.org/stc/SA941NW

## 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: SA941NW This certificate issued to: Portable Rock Production Part 42 of the CiviI Air Regulations.

Original Product -TypebertificateNumber: A-743 Make: Boeing Model: B75N1 Description of Type Design Change: Installation of a Pratt and Whitney R985-AN-5 engine with a Hamilton Standard 2D30/6101A-12 propeller, Servair type oil tank, modified air filter, and minor tubing changes in accordance with photographs 1 through 7.

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 B75N1, Serial Number 75-7702 only. A copy of this Certificate and Addendum No. SA941NW shall be maintained as part of the permanent records for the modified aircraft.

United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate (Continuation Sheet) Number: SA941Nw Supplemental Type Certificate ADDENDUM NO. SA941NW The conditions and limitations of Type Certificate Data Sheet A-743 apply except where superseded by the following:

Supplemental Type Certificate Data Sheet, which is part of STC SA941NW, prescribes the conditions and limitations under which the product for which Regulations. the STC was issued meets the airworthiness requirements of the Civil Air Supplemental Type Certificate HOLDER: Portable Rock Production I. BOEING B75N1 (LANDPLANE-NORMAL CATEGORY) AS MODIFIED BY STC SA941NW Engine: Pratt & Whitney R985-AN-5 Engine Limits: Takeoff and Maximum Continuous Power: 450 Hp at 2300 rpm and 37.0" Hg Fuel: 80 octane minimum grade aviation fuel Propeller and Propeller Limits: Hamilton Standard 2D30/6101A-12 550 Hp at 2300 rpm (maximum continuous) ALL ELSE IS THE SAME AS TYPE CERTIFICATE DATA SHEET A-743.

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

## Every issue (1)

- May 19, 1980: Issued, Current. [certificate](https://openairdocs.org/files/sha256/dc/d4/dcd4c8e0ffe48f2913f52114d27c420d28e5fc05e313d30d01d2ebd1a32db333)

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