To operate radio equipment over the territory of a contracting state both the operator and radio station must be suitably licensed by the state of registry of the aircraft.
The Flight Radiotelephony Operator's Licence (FRTOL) authorises a pilot to operate an Aircraft Radio Station in a UK registered aircraft.
The FRTOL is a national licence that can be issued as a stand-alone licence, but is normally held in conjunction with another Flight Crew licence.
A pilot undergoing training is authorised to operate the radio as a flight crew member.