# STC SA4-521

- Type: Supplemental type certificate
- Status: Current, Issued
- Holder: Glasco-Air Products, United States
- Description: Glass cloth application on control surfaces.
- Status date: January 1, 1960
- Product: Aircraft, Large Multi-Engine
- Certification basis: Part 21
- Data sheets: TCDS AR-10
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/13F389ACC4B22EC8862570D0007BAEA0.0001
- DRS record last changed: December 6, 2025
- Page: https://openairdocs.org/stc/SA4-521

## ADs that name it (0)

None.

## Approved models (1)

- General Dynamics Corporation Army L-13 Series (TCDS AR-10)

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