14 CFR § 121.535 - Responsibility for operational control: Flag operations.
(a) Each certificate holder conducting flag operations is responsible for operational control.
(b) The pilot in command and the aircraft dispatcher are jointly responsible for the preflight planning, delay, and dispatch release of a flight in compliance with this chapter and operations specifications.
(c) The aircraft dispatcher is responsible for -
(1) Monitoring the progress of each flight;
(2) Issuing necessary instructions and information for the safety of the flight; and
(3) Cancelling or redispatching a flight if, in his opinion or the opinion of the pilot in command, the flight cannot operate or continue to operate safely as planned or released.
(d) Each pilot in command of an aircraft is, during flight time, in command of the aircraft and crew and is responsible for the safety of the passengers, crewmembers, cargo, and airplane.
(e) Each pilot in command has full control and authority in the operation of the aircraft, without limitation, over other crewmembers and their duties during flight time, whether or not he holds valid certificates authorizing him to perform the duties of those crewmembers.
(f) No pilot may operate an aircraft in a careless or reckless manner so as to endanger life or property.