June 14, 1943: Accompanying a raid by 197 British Lancaster bombers against Oberhausen, Germany, five British Beaufighter night fighters make the first operational use of Serrate, a radar detector & homing device that allows them to home in on German night fighters employing the Lichtenstein airborne radar from up to 80 km (50 mi) away & intercept them. The Beaufighters do not intercept any German aircraft during the raid, however, & 17 British bombers are lost.
