World War II Examples of planes that were classified as day fighters were the Supermarine Spitfire and Messerschmitt Bf 109. Both were excellent interceptors, but were also found in roles such as fighter-bomber and reconnaissance. However, the weight of the radar systems needed to effectively track down enemy bombers at night was such that these smaller aircraft simply couldn't carry them given the electronics of the day. This led to the use of twin-engine aircraft like the Bristol Beaufighter and Messerschmitt Bf 110 as dedicated night fighters, at which point the term day fighter began to be used.
World War II Examples of planes that were classified as day fighters were the Supermarine Spitfire and Messerschmitt Bf 109. Both were excellent interceptors, but were also found in roles such as fighter-bomber and reconnaissance. However, the weight of the radar systems needed to effectively track down enemy bombers at night was such that these smaller aircraft simply couldn't carry them given the electronics of the day. This led to the use of twin-engine aircraft like the Bristol Beaufighter and Messerschmitt Bf 110 as dedicated night fighters, at which point the term day fighter began to be used.