# STC SA01222SE - Type: Supplemental type certificate - Status: Current, Amended - Holder: Merlyn Products Inc., United States - Description: Modification of the existing fuel system to increase its capacity - Applied: April 9, 2003 - Status date: May 20, 2008 - Product: Aircraft, Small Multi-Engine - Certification basis: Part 3, Part 21 - Data sheets: [TCDS 6A1](https://openairdocs.org/tcds/6A1) - Certificate PDF: https://openairdocs.org/files/sha256/c0/ea/c0eaa9b4c0091d61591b836c7de2a57f406c44a691022843654cdb113cff7422 - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/8742FF5CD5995A858625745C00757B25.0001 - DRS record last changed: December 5, 2025 - Page: https://openairdocs.org/stc/SA01222SE ## ADs that name it (0) None. ## Approved models (4) - Twin Commander Aircraft Corporation 500-A ([TCDS 6A1](https://openairdocs.org/tcds/6A1)) - Twin Commander Aircraft Corporation 500-B ([TCDS 6A1](https://openairdocs.org/tcds/6A1)) - Twin Commander Aircraft Corporation 500-S ([TCDS 6A1](https://openairdocs.org/tcds/6A1)) - Twin Commander Aircraft Corporation 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. United States of America Department of Transportation_Federal Aviation Administration Supplemental Type Certificate Number SA01222SE 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: 500A, B, S, and U Description of the Type Design Change : Modification of the existing fuel system to increase its capacity by the installation of additional fuel tanks and associated hardware per Merlyn Products, Inc., Top Drawing List 38-TDL-11, Rev. A, dated October 23, 2007, 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 these models on which other previously approved modifications are incorporated unless it is determined by that the relationship between this change and any of those other previously approved modifications, including changes in type design, will introduce no adverse effect upon the airworthiness of that aircraft. A copy of this certificate and Airplane Flight Manual Supplement 38-11-AFMS, Rev. C, dated May 20, 2008, 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. This certificate and the supporting data which is the ba sis for approval shall remain in effect until surrendered, suspended, revoked, or a termination date is otherwise established by the Administrator of the Federal Aviation Administration. Date of application: April 9, 2003 Date reissued: Date of issuance June 4, 2003 Date amended: May 20, 2008 (Signature) Acting Manager, Seattle Aircraft Certification Office (Title) ## Every issue (1) - May 20, 2008: Amended, Current. [certificate](https://openairdocs.org/files/sha256/c0/ea/c0eaa9b4c0091d61591b836c7de2a57f406c44a691022843654cdb113cff7422) --- 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.