What communication system allows pilots to converse when there’s no control tower available?

The correct answer is the Common Traffic Advisory Frequency (CTAF). This communication system is essential for pilots operating in areas without an air traffic control tower. The CTAF is designated for pilots to relay their positions, intentions, and other essential information to one another, enhancing situational awareness and safety. Pilots use this frequency to communicate their actions while approaching or departing from an airport, allowing them to coordinate their movements with other aircraft in the vicinity.

While UNICOM is also used at non-towered airports, it primarily serves non-air traffic control communications, such as reporting fuel availability or requesting services. FIS (Flight Information Service) provides pilots with weather and flight information but does not facilitate direct pilot-to-pilot communication. AFTN (Aeronautical Fixed Telecommunication Network) pertains to the exchange of aeronautical messages rather than real-time voice communication for pilots operating in uncontrolled airspace.