One hour after take-off from Beauvais, France, for a scheduled night passenger flight to London-Gatwick Airport, the aircraft reported over Lydd at FL60. Shortly afterwards there was a complete failure of the aircraft’s radio communications and radio navigational equipment. The crew were unable to locate or remedy the cause of the failure and, in view of the navigational difficulties posed by low cloud over S.E. England, the captain decided to return to Beauvais where conditions were thought to be better. The aircraft then descended through cloud over the English Channel, and the flight continued in visual contact over the sea. About 1 hour after the failure occurred, the lights of a town on the French coast were sighted. After flying up and down the coast for some time, the crew were unable to establish the aircraft’ s position and, rather than attempt to continue the flight overland in the poor weather conditions obtaining, the captain decided to ditch the aircraft in the surf near the lights of the town, which proved to be Le Tr‚port. After circling the area for about 40 minutes, during which time the passengers were briefed and prepared for the ditching, a successful wheels-up alighting was made obliquely towards the beach, and the aircraft came to rest in shallow water about 50 yards off-shore. The passengers and crew waded ashore safely, the aircraft later breaking up, as a result of the action of the tide and the waves, before it could be salvaged. Probable cause: (a) The design of the aircraft’s electrical installation in which no provision was made to, prevent the total interruption of radio communication and radio navigation in the event of a failure at the level of the single main supply fuse. (b) The failure of the main supply fuse probably of insufficient rating and the fact that the crew was not able to rectify the failure. (c) The inadequate attention paid by the crew to its dead reckoning navigation, both before and after the radio failure.