14 CFR § 91.1005

Except as provided in § 91.321 or § 91.501, no owner may carry persons or property for compensation or hire on a program flight.

During the term of the multi-year program agreements under which a fractional owner has obtained a minimum fractional ownership interest in a program aircraft, the flight hours used during that term by the owner on program aircraft must not exceed the total hours associated with the fractional owner's share of ownership.

No person may sell or lease an aircraft interest in a fractional ownership program that is smaller than that prescribed in the definition of “minimum fractional ownership interest” in § 91.1001(b)(10) unless flights associated with that interest are operated under part 121 or 135 of this chapter and are conducted by an air carrier or commercial operator certificated under part 119 of this chapter.