14 CFR § 121.569 - Equipment interchange: Domestic and flag operations.
(a) Before operating under an interchange agreement, each certificate holder conducting domestic or flag operations shall show that -
(1) The procedures for the interchange operation conform with this chapter and with safe operating practices;
(2) Required crewmembers and dispatchers meet approved training requirements for the airplanes and equipment to be used and are familiar with the communications and dispatch procedures to be used;
(3) Maintenance personnel meet training requirements for the airplanes and equipment, and are familiar with the maintenance procedures to be used;
(4) Flight crewmembers and dispatchers meet appropriate route and airport qualifications; and
(5) The airplanes to be operated are essentially similar to the airplanes of the certificate holder with whom the interchange is effected with respect to the arrangement of flight instruments and the arrangement and motion of controls that are critical to safety unless the Administrator determines that the certificate holder has adequate training programs to insure that any potentially hazardous dissimilarities are safely overcome by flight crew familiarization.
(b) Each certificate holder conducting domestic or flag operations shall include the pertinent provisions and procedures involved in the equipment interchange agreement in its manuals.