14 C.F.R. § 21.19 : Aeronautics and Space — FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION — AIRCRAFT — CERTIFICATION PROCEDURES FOR PRODUCTS AND ARTICLES — TYPE CERTIFICATES — Changes requiring a new type certificate

Each person who proposes to change a product must apply for a new type certificate if the FAA finds that the proposed change in design, power, thrust, or weight is so extensive that a substantially complete investigation of compliance with the applicable regulations is required.