# STC SA1841NM

- Type: Supplemental type certificate
- Status: Current, Reissued
- Holder: Twin Otter STC Holdings, LLC, United States
- Description: Installation of larger windows and the lowering of the seats.
- Applied: March 6, 1982
- Status date: August 3, 2026
- Product: Aircraft, Small Airplane
- Certification basis: Part 23
- Data sheets: [TCDS A9EA](https://openairdocs.org/tcds/A9EA)
- Certificate PDF: https://openairdocs.org/files/sha256/24/0b/240b650f1b465a641321d4278bf586139abfb2d332bbe5508df69873416ede10
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/DRSDOCID123245520220260910144804.0001
- DRS record last changed: September 10, 2026
- Page: https://openairdocs.org/stc/SA1841NM

## ADs that name it (0)

None.

## Approved models (5)

- De Havilland Aircraft of Canada Limited DHC-6-1 ([TCDS A9EA](https://openairdocs.org/tcds/A9EA))
- De Havilland Aircraft of Canada Limited DHC-6-100 ([TCDS A9EA](https://openairdocs.org/tcds/A9EA))
- De Havilland Aircraft of Canada Limited DHC-6-200 ([TCDS A9EA](https://openairdocs.org/tcds/A9EA))
- De Havilland Aircraft of Canada Limited DHC-6-300 ([TCDS A9EA](https://openairdocs.org/tcds/A9EA))
- De Havilland Aircraft of Canada Limited DHC-6-400 ([TCDS A9EA](https://openairdocs.org/tcds/A9EA))

## 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.

SA1841NM Twin Otter STC Holdings, LLC 2875 East Patrick Lane, Suite D Las Vegas, NV 89120 Part 23 Title 14 CFR A9EA De Havilland Aircraft of Canada DHC-6 Series The approval of this change in type design applies to the basic aircraft of the specified model that is otherwise unmodified. This approval should not be extended to other aircraft of this model on which other previously approved modifications are incorporated unless it is determined by the (See Continuation Sheet Page 3 of 3) 03/06/1982 03/21/2002 08/03/2026 03/11/1983 for Manager, West Certification Branch 3 Installation of larger windows and the lowering of the seats in accordance with FAA sealed Consulting Aerospace Engineers, Inc. MDL Number GRC-1-1007 Revision H, February 14, 1983 or later FAA approved revision.

SA1841NM 08/03/2026 3

SA1841NM 08/03/2026 Limitations and Conditions Continued:

the installer that the interrelationship between this change and any of those other previously approved modifications will introduce no adverse effect upon the airworthiness of that 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.

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## Every issue (1)

- August 3, 2026: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/24/0b/240b650f1b465a641321d4278bf586139abfb2d332bbe5508df69873416ede10)

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