# STC SA4-41

- Type: Supplemental type certificate
- Status: Current, Issued
- Holder: Northwest Airlines Inc, United States
- Description: Structure, power plant, systems and equipment modification.
- Status date: January 1, 1960
- Product: Aircraft, Large Multi-Engine
- Certification basis: Part 21
- Data sheets: [TCDS 6A3](https://openairdocs.org/tcds/6A3), [TCDS 6A4](https://openairdocs.org/tcds/6A4), [TCDS A-781](https://openairdocs.org/tcds/A-781)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/A80B11F776FC125F862570D0005294D1.0001
- DRS record last changed: December 5, 2025
- Page: https://openairdocs.org/stc/SA4-41

## ADs that name it (0)

None.

## Approved models (3)

- McDonnell Douglas Corporation DC-6 ([TCDS A-781](https://openairdocs.org/tcds/A-781))
- McDonnell Douglas Corporation DC-6 Series ([TCDS 6A3](https://openairdocs.org/tcds/6A3))
- McDonnell Douglas Corporation DC-6B (Navy R6D-1Z) ([TCDS 6A4](https://openairdocs.org/tcds/6A4))

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