Lockheed XP-58 Chain Lightning
In April 1943, Lockheed was tasked to build a twin-engined, two-seat fighter to be called XP-58 Chain Lightning. The idea behind this concept was the notion that a brute-sized, awesomely-armed escort fighter was needed. The first prototype flew on D-day, 6 June 1944, but by this time the role of escort fighter was fulfilled by the Xp-58's illustrious forebear, the P-38 Lightning, as well as the Republic P-47 Thunderbolt and North American P-51 Mustang. The second prototype was never completed, and after some flying time, the tests on the first prototype was terminated in 1945, and the airframe was scrapped in 1947. Source: Fighters of the United States Air Force Published by Temple Press/Aerospace.