<sod >Eurocontrol, the European Organisation for the Safety of Air Navigation, said the computer failure at the NATS UK air traffic control centre in Swanwick, Hampshire, was affecting London and southern UK airspace and could cause "potentially severe" flight delays.< eod>< sod > Eurocontrol, the European Organisation for the Safety of Air Navigation, said the "computer failure" had occurred at the NATS UK air traffic control centre in Swanwick, Hampshire.< eod>