14 CFR § 119.5

A person authorized by the Administrator to conduct operations as a direct air carrier will be issued an Air Carrier Certificate.

A person not authorized to conduct direct air carrier operations, but authorized by the Administrator to conduct operations as a U.S. commercial operator, will be issued an Operating Certificate.

A person not authorized to conduct direct air carrier operations, but authorized by the Administrator to conduct operations when common carriage is not involved as an operator of any U.S.-registered civil airplane or powered-lift with a seat configuration of 20 or more passengers, or a maximum payload capacity of 6,000 pounds or more, will be issued an Operating Certificate.

A person authorized to engage in common carriage under part 121 or part 135 of this chapter, or both, shall be issued only one certificate authorizing such common carriage, regardless of the kind of operation or the class or size of aircraft to be operated.

A person authorized to engage in noncommon or private carriage under part 125 or part 135 of this chapter, or both, shall be issued only one certificate authorizing such carriage, regardless of the kind of operation or the class or size of aircraft to be operated.

A person conducting operations under more than one paragraph of §§ 119.21, 119.23, or 119.25 shall conduct those operations in compliance with—

The requirements specified in each paragraph of those sections for the kind of operation conducted under that paragraph; and

The appropriate authorizations, limitations, and procedures specified in the operations specifications for each kind of operation.

No person may operate as a direct air carrier or as a commercial operator without, or in violation of, an appropriate certificate and appropriate operations specifications. No person may operate as a direct air carrier or as a commercial operator in violation of any deviation or exemption authority, if issued to that person or that person's representative.

A person holding an Operating Certificate authorizing noncommon or private carriage operations shall not conduct any operations in common carriage. A person holding an Air Carrier Certificate or Operating Certificate authorizing common carriage operations shall not conduct any operations in noncommon carriage.

No person may operate as a direct air carrier without holding appropriate economic authority from the Department of Transportation.

A certificate holder under this part may not operate aircraft under part 121 or part 135 of this chapter in a geographical area unless its operations specifications specifically authorize the certificate holder to operate in that area.

No person may advertise or otherwise offer to perform an operation subject to this part unless that person is authorized by the Federal Aviation Administration to conduct that operation.

No person may operate an aircraft under this part, part 121 of this chapter, or part 135 of this chapter in violation of an air carrier operating certificate, operating certificate, or appropriate operations specifications issued under this part.