# STC SA3520WE

- Type: Supplemental type certificate
- Status: Current, Issued
- Holder: AiResearch Aivation Service Co, United States
- Description: Installation of Sperry SPZ-500 autopilot and Sperry SPI-80/81 flight directors.
- Status date: November 23, 1977
- Product: Aircraft, Large Multi-Engine
- Certification basis: Part 21
- Data sheets: [TCDS 2A15](https://openairdocs.org/tcds/2A15)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/B014CFFB2C8691B885256CC2000A98E4.0001
- DRS record last changed: December 6, 2025
- Page: https://openairdocs.org/stc/SA3520WE

## ADs that name it (0)

None.

## Approved models (3)

- Lockheed Aircraft Corporation 1329-23A ([TCDS 2A15](https://openairdocs.org/tcds/2A15))
- Lockheed Aircraft Corporation 1329-23D ([TCDS 2A15](https://openairdocs.org/tcds/2A15))
- Lockheed Aircraft Corporation 1329-25 ([TCDS 2A15](https://openairdocs.org/tcds/2A15))

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