# STC ST488SO

- Type: Supplemental type certificate
- Status: Current, Issued
- Holder: Southern Airways Company, United States
- Description: Installation of Butler National 6A VAC/10A ADD Area Navigation System with altitude alerting capabilities that meet requirements of FAR 91.51.
- Status date: January 28, 1972
- Product: Aircraft, Small Multi-Engine
- Certification basis: Part 21, Part 91
- Data sheets: [TCDS A10CE](https://openairdocs.org/tcds/A10CE), [TCDS A5CE](https://openairdocs.org/tcds/A5CE)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/5D45F75A70DF11FD85256CC300036046.0001
- DRS record last changed: December 6, 2025
- Page: https://openairdocs.org/stc/ST488SO

## ADs that name it (0)

None.

## Approved models (3)

- Learjet Inc. Learjet 23 ([TCDS A5CE](https://openairdocs.org/tcds/A5CE))
- Learjet Inc. Learjet 24 ([TCDS A10CE](https://openairdocs.org/tcds/A10CE))
- Learjet Inc. Learjet 25 Series ([TCDS A10CE](https://openairdocs.org/tcds/A10CE))

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.