To be eligible for flight in the United States, a potential pilot often needs to have an aircraft FCC license. More specifically, someone interested in being a pilot must meet certain criteria and have the ability to operate a radio transmitter from within the plane, if the plane is flying at a certain height. Depending on what airspace class the pilot is flying in, a radio is imperative because it is a way for pilots to communicate with traffic control towers. The FCC authorizes the use of frequencies. To actually have a radio station assigned to a pilot, he must get an aircraft FCC license for the privilege. It is another certification among a number of additional instrument and medical certifications that a pilot should expect to get in order to fly. None of this applies to sport or ultralight aircraft, because in those cases, the aircraft are not permitted to fly in a zone that would mandate radio contact.