Except for § 250.7, this part applies to every carrier, as defined in § 250.1, with respect to scheduled flight segments using an aircraft that has a designed passenger capacity of 30 or more passenger seats, operating in interstate air transportation or foreign air transportation with respect to nonstop flight segments originating at a point within the United States. Section 250.7 applies to any air carrier or foreign air carrier as those terms are defined in 49 U.S.C. 40102.