The Witteman-Lewis XNBL-1 (Night Bombardment - Long Distance) was the only Type XIII aircraft actually built. The Barling Bomber was named for its designer, Walter Barling. Because the aircraft was so large, it was assembled and tested at Wilbur Wright Field (later renamed Patterson Field and currently part of Wright-Patterson Air Force Base) because the main test facilities and flying field at nearby McCook Field were too small for the aircraft to take off and land safely.
Although the XNBL-1 was designed as a long range bomber, with a full load of fuel and bombs, its range was only 170 miles, about one-third the range of the NBS-1 Short Distance bomber. Only one prototype was built for testing and its disappointing performance did not merit production. The Barling Bomber had six engines, three wings and a 10-wheel landing gear. The most significant feature of the aircraft was its wing span of 120 feet. An aircraft as big as the XNBL-1 would not be produced until 1935 when the XB-15 with a 149-foot span was built (Note: the B-17 wing span is about 104 feet).
TECHNICAL NOTES: Armament: Seven .30-cal. machine guns and up to 5,000 lbs. of bombs Engines: Six Liberty 12-As of 420 hp each Maximum speed: 96 mph. at sea level Cruising speed: 61 mph Service ceiling: 7,725 ft. Range: Approx. 170 miles with full bomb load (varied by bomb load carried) Span: 120 ft. 0 in. Length: 65 ft. 0 in. Height: 27 ft. 0 in. Weight: 32,203 lbs. gross Crew: Six Serial number: AS 64215 (a second prototype was ordered with S/N AS 64216 but was canceled before construction began)