Final answer:
According to aviation regulations, a pilot must notify the relevant authorities as soon as practicable about any changes to the route, destination, or departure aerodrome of a flight to ensure safety and proper coordination.
Step-by-step explanation:
According to CAR 602.76(3) and (4), a pilot shall notify an air traffic control unit, a flight service station, a community aerodrome radio station or the responsible person, of any change to: (c) the route of flight, (b) the destination of the flight; or (a) the departure aerodrome. These notifications are critical for maintaining the safety and efficiency of air traffic control and ensuring that the appropriate support services and emergency services are informed of a flight's status and can plan accordingly. The regulation highlights the importance of clear communication between pilots and air traffic control to avoid misunderstandings and potential safety hazards.