Portishead Radio communicated with aircraft as far back as the 1930s, when contact with the international flying boats regularly took place.
There was also monitoring of aircraft radio communication during WW2.
As the Maritime Radio business began to decline at the end of the 1980s, a formal Aeronautical Radio service was established, using the GKX series of callsigns.
Early customers included Dan-Air and the UK Fisheries Patrol aircraft.
The service began to expand substantially in the 1990s. Charter Airlines and established National Airlines began to use the service regularly.
Britannia, AIR2000, Monarch, British Airways and other UK companies were amongst the regular customers. In addition, freight companies like Heavylift utlised GKX on a daily basis. The RAF "Ascot" aircraft were also regularly in contact.
GKX became the European hub station of Eastern Airlines, as well as being the main communications facility for Britannia Airlines.
Many individual pilots set up their own private accounts with the station, and regular propagation forecasts were produced and distributed to customers to assist with frequency selection.
An Inmarsat-based service for aircraft called "Skyphone" was established and administered from the station, although this was not often used.
Not only aircraft used the service - relief agencies and industrial companies from remote locations used GKX for radiotelephone calls.
During both Gulf Wars, many calls were handled from units from both British and American service personnel.
Communication with Richard Branson's Virgin Balloon was a regular occurence, with phone patches to international media taking place via GKX.
Sadly, with the demise of the Maritime Radio service, the Aeronautical service was closed at the same time.
The possibility of amalgamating with the British Airways "Speedbird" service was discussed but not taken up.
The service closed on 30th April 2000.