Callsign CLX is Cargolux
WHAT AIRLINE IS CLX?
CLX is the ICAO three-letter callsign prefix for Cargolux. When a radio scanner, flight tracker or radar scope shows a flight like CLX123 or CLX45XY overhead, that's a Cargolux aircraft talking to air traffic control.
Spot one yourself: open the live scope, enter your postcode, and tap any blip whose callsign starts with CLX for its type, registration, route and photo.