Northrop P-61 Black Widow
The Northrop P-61 Black Widow, named for the American spider, was the first operational U.S. warplane designed as a night fighter, and the first aircraft designed to use radar. The P-61 had a crew of three: pilot, gunner, and radar operator. It was armed with four 20 mm Hispano M2 forward-firing cannons mounted in the lower fuselage, and four .50 in M2 Browning machine guns mounted in a remote-controlled dorsal gun turret.
Although not produced in the large numbers of its contemporaries, the Black Widow was effectively operated as a night-fighter by United States Army Air Forces squadrons in the European Theater, the Pacific Theater, the China Burma India Theater and the Mediterranean Theater during World War II. It replaced earlier British-designed night-fighter aircraft that had been updated to incorporate radar when it became available. After the war, the P-61—redesignated the F-61—served in the United States Air Force as a long-range, all-weather, day/night interceptor for Air Defense Command until 1948, and Fifth Air Force until 1950.