The Soviet Union had the world's best radar - until a Cold War plane crash gave Britain the chance to pinch it. Michael Smith reports. The Cold War was at its peak when on April 6, 1966, a top-secret Soviet fighter aircraft crashed into the Havelsee, a lake straddling the British and Russian sectors of Berlin. The British mounted a salvage operation, promising to return the aircraft and the bodies of its two pilots to the Russians. But as a barge and a crane were set up on the lake's surface to recover the aircraft, beneath the surface there was...