# STC SA00987CH

- Type: Supplemental type certificate
- Status: Current, Reissued
- Holder: Landmark Aviation, United States
- Description: Installation of AlliedSignal two tube EFIS-50 on co-pilot's panel with Honeywell FZ500 flight director.
- Applied: January 4, 1999
- Status date: February 3, 2006
- Product: Aircraft, Small Multi-Engine
- Certification basis: Part 21, Part 23
- Data sheets: [TCDS A1WI](https://openairdocs.org/tcds/A1WI)
- Certificate PDF: https://openairdocs.org/files/sha256/b0/96/b096a7a72c8321fb649c68fb68cca1c14ea25d7a7e62a5b32557bf759e9a7bc3
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/3E66680B0E7F7067862575FC0065C265.0001
- DRS record last changed: December 6, 2025
- Page: https://openairdocs.org/stc/SA00987CH

## ADs that name it (0)

None.

## Approved models (1)

- The Cessna Aircraft Company 525 ([TCDS A1WI](https://openairdocs.org/tcds/A1WI))

## 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.

Part 23 of the Federal Aviation Regulations.

Installation of an Allied Signal two tube EFIS-50 on Co-pilot’s panel with Honeywell FZ500 Flight Director in accordance with ElectroSonics Drawing No. ES525-720250-01, Revision 1, dated February 2, 1999 or later FAA approved revision.

1. Compatibility of this design change with previously appr oved modifications must be determined by the installer.

2. The aircraft must be maintained in accordance with F AA Approved Maintenance Manual Supplement, document number ES525- 720250-200, Initial Release, dated February 02, 1999, or later FAA approved revision in addition to the basic airplane maintenance manuals.

3. FAA Approved Flight Manual Supplem ent, Document number ES525-720250-100, dated February 02, 1999 or later FAA approved revision is a required part of this STC.

4. 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.

Landmark Aviation 1200 North Airport Drive Springfield, IL 62707 A1WI Make : Cessna Model : 525 Date of application : January 04, 1999

Date of issuance : February 02, 1999

Date reissued : February 03, 2006

( Signature) Charles L. Smalley Manager, Systems and Flight Test Branch Chicago Aircraft Certification Office

( Title)

## Every issue (1)

- February 3, 2006: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/b0/96/b096a7a72c8321fb649c68fb68cca1c14ea25d7a7e62a5b32557bf759e9a7bc3)

---
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.