Which messages are controllers authorized to transmit?

Controllers are authorized to transmit messages that are necessary for air traffic control because these communications are essential for ensuring the safe and efficient movement of aircraft in the airspace. This includes providing instructions, clearance, information regarding weather and traffic, and any pertinent data that assists pilots in safely navigating their flight paths. Such messages are fundamental to maintaining situational awareness, preventing collisions, and managing the overall flow of air traffic.

Messages of personal interest or those that increase the length of communications do not serve the primary goal of air traffic control and can lead to confusion, delays, or unsafe situations. Similarly, messages that are unrelated to air safety have no bearing on the operational responsibilities of a controller and could detract from the efficiency of the communication process. Thus, the focus remains firmly on safety-related communications, underscoring the critical role of controllers in managing air traffic.