# STC ST540SO

- Type: Supplemental type certificate
- Status: Current, Issued
- Holder: Survival Products Inc, United States
- Description: Installation includes: four interior overhead emergency lights powered by power supply located in forward fuselage; exterior overwing emergency light in wing fillet, one on each side, powered by power supply in aft fuselage; emergency light control switches installed in both flight and passenger compartments.
- Status date: June 15, 1973
- Product: Aircraft, Large Multi-Engine
- Certification basis: Part 21
- Data sheets: [TCDS A-669](https://openairdocs.org/tcds/A-669)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/31EBCCF215ED2A8A85256CC300036074.0001
- DRS record last changed: December 6, 2025
- Page: https://openairdocs.org/stc/ST540SO

## ADs that name it (0)

None.

## Approved models (2)

- McDonnell Douglas Corporation DC-3A Series ([TCDS A-669](https://openairdocs.org/tcds/A-669))
- McDonnell Douglas Corporation DC-3C Series ([TCDS A-669](https://openairdocs.org/tcds/A-669))

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From OpenAirDocs.org, an independent open copy of FAA and NTSB data. Only the Federal Register edition on govinfo.gov is the official legal text of an AD.