In an aircraft, individual computers are connected by a data bus to a central controller system. To reprogram, i.e. load a new program into, any one of the computers, each computer is equipped with a radio interface module and a radio antenna to establish a radio link with a central computer unit that provides and transmits the new program via the radio link at a high data transfer rate, e.g. above 200 kByte per second. The relatively slow physical data bus is not used for transmitting or loading the new program. Each computer has a base system program loaded and executed therein, to control, monitor or otherwise support the process of loading the new program, and to test the new program once it has been loaded.