# STC SA02450SE - Type: Supplemental type certificate - Status: Current, Issued - Holder: Merlyn Products Inc., United States - Description: Installation of the Lycoming IO-540-M1C5 engine and Hartzell HC-C3YR-2UF/FC8468()-6R propeller. - Applied: May 29, 2014 - Status date: September 1, 2015 - Product: Aircraft, Small Airplane - Certification basis: Part 3, Part 21 - Data sheets: [TCDS 6A1](https://openairdocs.org/tcds/6A1) - Certificate PDF: https://openairdocs.org/files/sha256/3a/58/3a58de5eb9169595c0ef5af1ceb98d0783c9aa60752d1763f63557b232062620 - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/5D56292BFE7F1ECC86257EB50055B814.0001 - DRS record last changed: December 6, 2025 - Page: https://openairdocs.org/stc/SA02450SE ## ADs that name it (0) None. ## Approved models (3) - Twin Commander Aircraft LLC 500-B ([TCDS 6A1](https://openairdocs.org/tcds/6A1)) - Twin Commander Aircraft LLC 500-S ([TCDS 6A1](https://openairdocs.org/tcds/6A1)) - Twin Commander Aircraft LLC 500-U ([TCDS 6A1](https://openairdocs.org/tcds/6A1)) ## 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. Number SA02450SE This certificate, issued to Merlyn Products, Inc. 7500 West Park Drive Spokane, WA 99224 Part 3 of the Civil Air Regulations. Original ProductType Certificate Number: 6A1 Make: Twin Commander Model: 500B, 500S, 500U Description of the Type Design Change: Installation of the Lycoming IO-540-M1C5 engine and Hartzell HC-C3YR-2UF/FC8468()-6R propeller in accordance with Merlyn Products, Inc. (MPi) Report 37-21, Revision N/C, dated April 24, 2015, or later Federal Aviation Administration (FAA) approved revision. Manufactured in accordance with MPi Top Drawing List 37-21-TDL, Revision N/C, dated May 4, 2015, or later FAA-approved revision. Maintained in accordance with MPi Instructions for Continued Airworthiness (ICA) 37-21-ICA, Revision N/C, dated April 30, 2015, or later FAA-accepted revision. Operated in accordance with MPi Airplane Flight Manual Supplement (AFMS) 37-21-AFMS, Revision N/C, dated August 28, 2015, or later FAA-approved revision. Limitations and Conditions: Approval of this change in type design applies to the above model aircraft only. This approval should not be extended to other aircraft of this model series unless the installer determines that the relationship between this change and any other previously incorporated approved modifications will introduce no adverse effect upon the airworthiness of that aircraft. A copy of this certificate, ICA, and AFMS must be maintained as part of the permanent records for the modified aircraft. 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. Date of application: May 29, 2014 Date reissued: Date of issuance: September 1, 2015 Date amended: (Signature) Manager, Seattle Aircraft Certification Office (Title) ## Every issue (1) - September 1, 2015: Issued, Current. [certificate](https://openairdocs.org/files/sha256/3a/58/3a58de5eb9169595c0ef5af1ceb98d0783c9aa60752d1763f63557b232062620) --- 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.