# STC SA02453AK - Type: Supplemental type certificate - Status: Current, Issued - Holder: Clearwater Air Inc, United States - Description: Increase maximum ramp weight to 11,050 lbs. and increase maximum takeoff weight to 11,000 lbs. when operating in restricted category for the special purpose of Forest Service and Wildlife Conservation/Aerial Survey. - Applied: March 20, 2015 - Status date: August 28, 2015 - Product: Aircraft, Small Airplane - Certification basis: Part 3, Part 21 - Data sheets: [TCDS 2A4](https://openairdocs.org/tcds/2A4) - Certificate PDF: https://openairdocs.org/files/sha256/2e/cc/2ecc01840ab178acbc2717160b97532be5b8ae04edfd192000d2d9ba2139f11d - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/F2726EF3974F1F2D86257EB30072A81F.0001 - DRS record last changed: December 6, 2025 - Page: https://openairdocs.org/stc/SA02453AK ## ADs that name it (0) None. ## Approved models (3) - Twin Commander Aircraft LLC 690A ([TCDS 2A4](https://openairdocs.org/tcds/2A4)) - Twin Commander Aircraft LLC 690B ([TCDS 2A4](https://openairdocs.org/tcds/2A4)) - Twin Commander Aircraft LLC 690C ([TCDS 2A4](https://openairdocs.org/tcds/2A4)) ## 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. This certificate issued to Clearwater Air, Inc.. 1100 Merrill Field Dr Anchorage, AK 99501 Part 3 of the Civil Air Regulations Original Product – Type Certificate Number: 2A4 Make: Twin Commander Aircraft LLC Model: 690A, 690B, and 690C Description of Type Design Change: Increase maximum ramp weight to 11,050 lbs. and increase maximum takeoff weight to 11,000 lbs. when operating in restricted category for the special purpose of Forest Service and Wildlife Conservation/Aerial Survey. 1) The installer must determine whether this design change is compatible with previously approved modifications. 2) The increased weight is authorized only when operating in restricted category for the special purpose of Forest Service and Wildlife Conservation/Aerial Survey. 3) If the aircraft is landed at a landing weight of more than 9600 lbs (690A) or 9675 lbs (690B, 690C) or if a take off is aborted at more than 10,250 lbs (690A) or 10,325 lbs (690B, 690C), an “Abnormal Ground Loads Inspection” must be accomplished prior to further flight in accordance with Twin Commander 690A/690B Maintenance Manual Section XIII, pages 13-165 and 13-166 or Twin Commander 690C Maintenance Manual Chapter 5, Section 05-50-00, page 201. 4) This approval is limited to aircraft listed in Clearwater Air Gross Weight Increase Aircraft Serial Number Eligibility Report 081915-1, Revision 0, dated August 19, 2015, or later FAA approved revision. 5) A copy of this Certificate and FAA Approved Flight Manual Supplement 062315-1, Revision 0, dated August 28, 2015, or later FAA approved revision, must be maintained as part of the permanent records for the modified aircraft. 6) Airworthiness Directive compliance must be accomplished based on the intervals for survey usage, when given. 7) For Instructions for Continued Airworthiness (ICA), refer to Clearwater Air, Inc. Instructions for Continued Airworthiness 060915-01, Revision Initial Issue, dated June 9, 2015, or later FAA accepted revision. 8) If the holder agrees to permit another person to use this certificate to alter a product, the holder must give the other person written evidence of that permission. Date of application: March 20, 2015 Date reissued: Date of issuance: August 28, 2015 Date amended: (Signature) August A. Asay Manager, Anchorage Aircraft Certification Office (Title) ## Every issue (1) - August 28, 2015: Issued, Current. [certificate](https://openairdocs.org/files/sha256/2e/cc/2ecc01840ab178acbc2717160b97532be5b8ae04edfd192000d2d9ba2139f11d) --- 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.