The Lockheed P-38 Lightning was one of the best-known Army Air Forces fighters that flew in World War II. It was already in mass production before the war started for the United States, and production lasted until 1945. With a wingspan of 52 feet; a length of 37 feet, 10 inches; and a height of 9 feet, 10 inches, the P-38s had maximum speeds ranging from 390 miles per hour for the basic P-38 to 414 mph for the P-38L. Except for the M model (a two-seater), all the P-38s were single-seat pursuit and long-range escort aircraft.