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 and 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 and intercept them. The Beaufighters do not intercept any German aircraft during the raid, however, and 17 British bombers are lost.
Beaufighter Mark IIF night fighter, R2270. The first production Beaufighter Mark IIF night fighter, R2270, fitted with dihedral tailplanes and equipped with AI Mark IV radar, in flight. This aircraft served with No. 406 Squadron RCAF. as in this photo some were fitted with Merlins engines.