# STC SA21GL

- Type: Supplemental type certificate
- Status: Current, Reissued
- Holder: Honeywell International Inc., United States
- Description: Installation of Grimes multi-plexed anti-collision light system.
- Applied: March 14, 1973
- Status date: June 4, 2007
- Product: Aircraft, Single-Engine
- Certification basis: Part 21
- Data sheets: [TCDS 3A12](https://openairdocs.org/tcds/3A12), [TCDS 3A13](https://openairdocs.org/tcds/3A13)
- Certificate PDF: https://openairdocs.org/files/sha256/30/3e/303e7898b12474036a2572a00a00c5ca61f4baf27c41025923e1ef81fc22b91c
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/174E9A8E617C18C586257317004B992A.0001
- DRS record last changed: December 6, 2025
- Page: https://openairdocs.org/stc/SA21GL

## ADs that name it (0)

None.

## Approved models (30)

- The Cessna Aircraft Company 172 ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- The Cessna Aircraft Company 172A ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- The Cessna Aircraft Company 172B ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- The Cessna Aircraft Company 172C ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- The Cessna Aircraft Company 172D ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- The Cessna Aircraft Company 172E ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- The Cessna Aircraft Company 172F (USAF T-41A) ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- The Cessna Aircraft Company 172G ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- The Cessna Aircraft Company 172H (USAF T-41A) ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- The Cessna Aircraft Company 172I ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- The Cessna Aircraft Company 172K ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- The Cessna Aircraft Company 172L ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- The Cessna Aircraft Company 172M ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- The Cessna Aircraft Company 172N ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- The Cessna Aircraft Company 172P ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- The Cessna Aircraft Company 182 ([TCDS 3A13](https://openairdocs.org/tcds/3A13))
- The Cessna Aircraft Company 182A ([TCDS 3A13](https://openairdocs.org/tcds/3A13))
- The Cessna Aircraft Company 182B ([TCDS 3A13](https://openairdocs.org/tcds/3A13))
- The Cessna Aircraft Company 182C ([TCDS 3A13](https://openairdocs.org/tcds/3A13))
- The Cessna Aircraft Company 182D ([TCDS 3A13](https://openairdocs.org/tcds/3A13))
- The Cessna Aircraft Company 182E ([TCDS 3A13](https://openairdocs.org/tcds/3A13))
- The Cessna Aircraft Company 182F ([TCDS 3A13](https://openairdocs.org/tcds/3A13))
- The Cessna Aircraft Company 182G ([TCDS 3A13](https://openairdocs.org/tcds/3A13))
- The Cessna Aircraft Company 182H ([TCDS 3A13](https://openairdocs.org/tcds/3A13))
- The Cessna Aircraft Company 182J ([TCDS 3A13](https://openairdocs.org/tcds/3A13))
- The Cessna Aircraft Company 182K ([TCDS 3A13](https://openairdocs.org/tcds/3A13))
- The Cessna Aircraft Company 182L ([TCDS 3A13](https://openairdocs.org/tcds/3A13))
- The Cessna Aircraft Company 182M ([TCDS 3A13](https://openairdocs.org/tcds/3A13))
- The Cessna Aircraft Company 182N ([TCDS 3A13](https://openairdocs.org/tcds/3A13))
- The Cessna Aircraft Company 182P ([TCDS 3A13](https://openairdocs.org/tcds/3A13))

## What the certificate says

Read from the PDF's text layer, without the form's printed wording; the layout is lost and the order can differ. The PDF is the record.

certifies that the change in the type design for the following product with the limitations and conditions therefor as specified hereon meets the airworthiness requirements specified under the certification basis on the applicable Data Sheets or Aircraft Specifications identified on Approved Grimes Model Eligibility List No. 34-1001.

Install Grimes Multiplexed Anticollision Light System in accordance with the data identified by the Part Number shown on Approved Model Eligibility List No. 34-1001.

1) This approval should not be extended to other aircraft of this model on which other previously approved modifications are incorporated unless it is determined by the installer that the interrelationship between this change and any of those other previously approved modifications will introduce no adverse effect upon the airworthiness of that aircraft.

2) If the holder agrees to permit another person to use this certificate to alter the product, the holder shall give the other person written evidence of that permission.

Honeywell International Inc.

550 Route 55 Urbana, OH 43078 Make : As shown on Approved Model Eligibility List Model : No. 34-1001.

Date of application : March 14, 1973

Date of issuance : May 9, 1973

Date reissued : May 5, 1988; November 5, 1991; June 4, 2007

( Signature) Charles L. Smalley System & Flight Test Branch Chicago Aircraft Certification Office

( Title)

## Every issue (1)

- June 4, 2007: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/30/3e/303e7898b12474036a2572a00a00c5ca61f4baf27c41025923e1ef81fc22b91c)

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