STC SA00169SE

Number SA00169SE 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: Install the Lycoming IO-540-M1C5 engine and Hartzell HC- C3YR-2UF/FC8468()-6R propeller in accordance with Merlyn Products, Inc. report Number 37-11, Revision N/C, dated September 9, 1999, and Merlyn Products Drawing List 37-TDL, Revision B, dated September 29, 1999, or later FAA approved revisions to either of these documents; and increase the maximum gross weight for these airplanes from 6750 pounds to 7000 pounds.

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 engines of these models on which other previously approved modifications are incorporated unless it is determined 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 Merlyn Products Airplane Flight Manual Supplement, dated June 2, 2000, 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 8, 1994 Date reissued:

Date of issuance: August 4, 1995 Date amended: June 2, 2000

(Signature) Acting Manager, Seattle Aircraft Certification Office (Title)