Witteman - Lewis XNBL - 1 The Wittemann - Lewis NBL - 1 " Barling Bomber " was an experimental long - range , heavy bomber built for the United States Army Air Service in the early 1920s . Although unsuccessful as a bomber , it was an early attempt at creating a strategic bomber . Design and development . Development of the XNBL - 1 ( Experimental Night Bomber , Long Range ) Barling Bomber is generally attributed to Gen . William " Billy " Mitchell , who in 1919 discovered Walter H . Barling , who had previously worked for the Royal Aircraft Factory . Mitchell asked Barling to design a bomber capable of carrying enough bombs to sink a battleship . Mitchell ' s goal was to demonstrate the effectiveness of airpower by sinking a battleship from the air , and needed a large , strategic bomber in order to accomplish this feat . Mitchell projected the cost of two prototype bombers at $ 375 , 000 . On 15 May 1920 , the Army Engineering Division sought bids for the construction of a bomber based on Barling ' s sketches , with the requirement that it be capable of carrying a bomb load , to an altitude of at a speed of no less than . Barling had previously designed the Tarrant Tabor , which was similar in concept but was destroyed in a fatal nose - over crash on its first flight in 1919 . The nose - over had probably been caused by the high placement of two of the engines . Like the Tabor , the Barling Bomber was a large six - engined triplane with a cigar - shaped fuselage . Unlike its predecessor , the Barling had all of its engines mounted level with the fuselage . The aircraft used three wings , but was not actually a triplane . More correctly , it was a two - and - a - half wing aircraft . The middle wing had no control surfaces , and was shorter and narrower than the two primary wings . The top and bottom wings had a chord of , and each had a surface area of about . The stabilizer and elevator surfaces were with an chord . The fins and rudders looked like a box kite , and had a surface area of . The undercarriage consisted of 10 wheels , including two wheels mounted towards the front of the aircraft ( to prevent a nose - over on takeoff ) and a tail skid . The Engineering Division was forced to use Liberty engine s because of an abundant supply of the engines . To power the Barling , four 420 hp Liberty engines were mounted between the lower and middle wings in a tractor arrangement , and an additional two in a pusher position . The gross weight of the bomber was 42 , 569 lbs . It had a fuel capacity of 2 , 000 gallons , and carried 181 gallons of oil . Two pilots set in separate cockpits either side of the fuselage , while a bombardier sat in the nose . One or two flight engineers sat behind the cockpits to help tend the engines , a first for any aircraft . A radio operator and a navigator were seated next to them . The Barling was armed with seven . 30 - caliber Lewis machine gun s , which were operated from five stations . The gun stations gave the gunners a field of fire that covered practically the whole area around the bomber . Bomb racks were mounted in an enclosed bomb bay beneath the gasoline tanks . The bomb bay could accommodate any bomb in the air service inventory , including the 2 , 000 - and 4 , 000 - lb bombs that had been designed specifically to sink a battleship . The Barling incorporated bomb bay doors on the bottom of the fuselage , one of the first aircraft to feature such an innovation . Production . The winning bid for construction of the massive bomber went to the Wittemann - Lewis Company of Hasbrouck Heights , New Jersey . They received a contract to construct two aircraft at a cost of $ 375 , 000 . Due to increased costs and the number of design changes required the order was cut to one , by the time the aircraft was completed in October 1922 , the cost had risen from $ 375 , 000 for two bombers to $ 525 , 000 for one . Wittemann - Lewis had to absorb the cost overrun , and went out of business a few months after shipping the completed aircraft to Ohio . There were only six airfields in the country large enough to accommodate the massive bomber , and after careful consideration the decision was made to base it at Wilbur Wright Field in Fairfield , Ohio because of its close proximity to McCook Field , and its resources . The bomber was shipped by rail to Wilbur Wright Field in Fairfield , Ohio in May 1923 . After 94 days of assembly , the aircraft was ready for its maiden flight . Operational history . On 22 August 1923 , the Barling Bomber made its maiden flight from Wilbur Wright Field in Fairfield , Ohio . At the time it was by far the heaviest aircraft in the world , and remains large even by today ' s standards . On its first flight it was piloted by Lt . Harold R . Harris , and Lt . Muir S . Fairchild , future U . S . Air Force Vice Chief of Staff . The flight engineer was Douglas Culver . Barling flew along as a passenger . Critics had claimed that the bomber would roll all the way to Dayton before it ever took off , but the aircraft became airborne after a 13 - second , takeoff run . The flight lasted 28 minutes and reached an altitude of 2 , 000 ft ( 609 m ) . On 3 October 1924 , the aircraft set a duration record of 1 hour 47 mins for an aircraft " with 8 , 820 lbs ( 4 , 000 kgs ) useful load " . It also set a record in the same class for altitude with 4 , 470 ft ( 1 , 363 m ) . Although capable of carrying a 5 , 000 lb ( 2 , 300 kg ) bomb load , it was soon discovered that the aircraft was seriously underpowered , and performance was disappointing . The overly complex structure of three wings and their accompanying struts and bracing wires created so much interference drag that the six engines could barely compensate . Fully loaded , the XNBL - 1 had a range of only about 170 miles ( 270 km ) with a top speed of 96 mph ( 155 km / h ) . In contrast , the " short - range " Martin NBS - 1 had a range of about 450 miles ( 725 km ) and could carry a 2 , 000 lb ( 900 kg ) at the same speed . On a flight from Dayton , Ohio to a scheduled appearance at an airshow in Washington , DC , the Barling Bomber failed to fly over the Appalachian Mountains and had to turn around . A problem with water collecting in the aircraft ' s wings during rain storms necessitated the construction of a special hangar at a cost of $ 700 , 000 . The hangar was constructed in 1925 at the nearby Fairfield Air Depot . Although the XNBL - 1 was not put into production , it had advanced features such as aluminum fuselage components , adjustable multi - wheel undercarriage , separate compartments for crew , a flight engineer , electrical instruments and advanced engine controls . One unusual feature was that the incidence of the tailplane could be adjusted in flight using a lever in the cockpit . The XNBL - 1 was the largest aircraft built in the United States until the Boeing XB - 15 in 1935 . Frequently characterized by opponents of airpower as " Mitchell ’ s Folly " ( after Brig . - Gen . William " Billy " Mitchell , who had championed the project ) , in 1927 , the aircraft was disassembled by Air Service personnel and placed in storage at the Fairfield Air Depot . In 1929 , then - Major Henry H . " Hap " Arnold was assigned as commander of the Fairfield Air Depot . He submitted a Report of Survey to the Office of the Chief of Air Corps , asking permission to salvage parts from the stored bomber , and burn the rest . Several members of Congress still held an interest in the aircraft , and the request was denied . Maj . Arnold then submitted a similar request to burn the " XNBL - 1 " , omitting any mention of the name " Barling " . That request was approved , and the bomber was burned at Fairfield in 1930 . Although the Barling Bomber was considered a failure at the time , it led the way in the development of large , strategic bombers . Even Gen . " Hap " Arnold , who ordered it destroyed , later stated " if we look at it without bias , certainly [ the Barling ] had influence on the development of B - 17 s . . . and B - 29 s . " See also . Tarrant Tabor