Method for determining an identifier corresponding to a frequency set on a display unit of the cockpit and system of implementation

A system on board an aircraft used to determine an identifier of a communications centre with which an aircraft crew must enter into contact, the system comprising:

• a display unit to which a radio-communications frequency is written;
• a database comprising at least one list of the communications centers, their transmission/reception frequencies and their identifier;
• and
• a computer capable of:
• determining surroundings of the aircraft, determining frequencies of the communications centers possible in these surroundings, by sorting out those frequencies that are possible from among all the frequencies of the surroundings of the aircraft in order to determine communication centers liable to communicate with the aircraft on these frequencies;
• drawing up of a list of communications centers in the aircraft surroundings with their respective frequencies;
• then comparing the transmission/reception frequencies of the communications centers with the frequency displayed on the display unit;
• and when the frequency of a communications centre is identical to the displayed frequency, displaying on the aircraft display unit, the identifier of said communications centre having a frequency identical to the displayed frequency.