This is what some called "Mitchell's Folly". Officially known as the Witteman-Lewis XNBL-1 (Experimental Night Bomber - Long Range) and more commonly called the Barling Bomber after its designer, this behemoth was the product of idealistic passions that exceeded the technological realities of the day and ran head-on into a political storm that surrounded the future of America's military might during the 1920s.
If there was one thing above all else that Lt. Gen. Billy Mitchell took away from his experiences in World War I was the fact that the true future of warfare, both over land and at sea, lay in the development of air power, and more specifically, in strategic bombing. While the US Navy pressed for more and more dreadnaught battleships at great expense, Mitchell argued that bomber aircraft could secure a coastline much more efficiently than could the battleships, and for the price of one dreadnaught, a thousand bombers could be built, which could easily sink a battleship.Navy leadership was outraged at these claims - and the threat to their empire of surface ships - and thus the early 1920s was marked by rancorous disputes.
Mitchell, for his part, aimed to prove his perspective by turning the idea of a strategic, long-range bomber into reality, with the goal of a plane large enough to carry a bomb load capable of sinking a battleship. Earlier, he had met a gifted aircraft designer then working for the UK's Royal Aircraft Factory by the name of Walter Barling. He had designed the Tarrant Tabor, a British triplane bomber that was, when built, the world's largest airplane (the ungainly aircraft had suffered a fatal crash on its maiden flight; that fact, though, does not seem to have deterred Mitchell).
The two agreed that a large bomber was certainly feasible and Barling went to work for the Army Engineering Division and began sketching out his ideas. In 1920, specifications were issued and manufacturers were asked to bid on building two of the bombers.The plane was to be capable of carrying a 5,000 pound bomb load, fly to 10,000 feet and have a cruising speed of at least 100 mph. Witteman-Lewis, of Teterboro, New Jersey, won the bidding process.
As a product of political warfare, the design was subject to the pitfalls of political reality. The Army had a huge surplus of 420-hp V-12 Liberty engines at the end of WWI (over 20,000 had been built by the combined efforts of Buick, Ford, Cadillac, Lincoln, Packard and Marmon), and Congress had mandated that these be used up by any new aircraft projects before new engines could be procurred. To get enough power, Barling used six Liberty 12A engines, four as tractors, with two more as pushers mounted behind the two inboard tractors.
A number of innovative features were included in the design. The landing gear consisted of two main gear "bogies" featuring four wheels each plus a nose gear to prevent the kind of nose-over that the Tarrant Tabor had suffered. The pilot and copilot each had his own cockpit, and behind them there was a station for one or two flight engineers who would monitor the engines, a first for aviation. A navigator, a radio operator also had their own spaces, and a bombardier sat in the nose. Unlike earlier bombers, the XNBL-1 carried its bomb load internally, and utilized another first: bomb bay doors. For defense, seven machine guns were operated from five positions.
Components were built in New Jersey and the were shipped by rail to Wilbur Wright Field for final assembly. The plane's maiden flight took place on August 22, 1923, and was less than stellar (Barling hinself flew as a passenger on that flight). The result of the power compromises was that, while the plane could get off the ground easily enough - a little less than a thousand feet was needed - it couldn't really get much higher. The plane's service ceiling didn't go high enough to even allow the XNBL-1 to fly from Dayton to Washington: the Appalachians were too imposing of a mountain range (this was discovered as the plane was attempting to fly to an airshow in DC and had to turn around). The plane could only manage a top speed of 96 mph, and only had a 170-mile range, far less than would be expected from a long-range strategic bomber.
Almost immediately, the order for the second aircraft was cancelled. Despite the disappointing performance, the plane did manage to actually set a world record (not that it had much competition), carrying a 4,400 pound bomb load to 6,722 feet. When ordered, the two aircraft were projected to cost $375,000, but due to excessive cost overruns, the single aircraft built cost $525,000, and Witteman-Lewis had to absorb the difference, causing them to go out of buisness a few months after delivering the plane to the Army
The plane was eventually disassembled and stored in a large warehouse at Wilbur Wright Field. Major "Hap" Arnold discovered it there during a 1928 inspection tour, and determined to get rid of it. So much money had been invested in it, though, that some in Congress resisted Arnold's requests for permission to dispose of the Barling. Undeterred, Arnold subsequently submitted a request to Congress to "liquidate a warehouse containing excess materiel" with out disclosing what that materiel was or that the plane was part of it. This time Congress agreed, and the Barling quietly disappeared from history. The only remnants to survive are two of the ten original wheels, which are currently displayed at the Museum of the U.S. Air Force at Dayton.
All was not a total loss, however. The effort to build such a huge aircraft forced the design team to have to overcome a number of engineering hurdles, and the lessons learned were able to be applied directly to the next generation of large bombers, the B-15, B-17, B-19 and ultimately the B-29.