Witteman-Lewis XNBL

Witteman-Lewis XNBL-1
275px
AS 64215, "Barling Bomber" at St. Louis Air Meet 1923
Type	Heavy Bomber
Manufacturer	Witteman-Lewis
Designed by	Walter Barling
Maiden flight	22 August 1923
Retired	1928
Status	Experimental
Primary user	United States Army Air Service
Number built	1
Unit cost	$525,000

The Witteman-Lewis XNBL-1 (also known as the Barling Bomber) was an experimental long-range, heavy bomber built for the United States Army Air Service in the early 1920s, an early attempt at creating a strategic bomber.

Design and development

The XNBL-1(Experimental Night Bomber, Long Range) was designed by Walter Barling, who had previously designed the Tarrant Tabor, which was similar in concept but was destroyed in a fatal crash on its first flight in 1919. Like the Tabor, the Barling Bomber was a large six-engined triplane with a cigar-shaped fuselage. Unlike its predecessor, the XNBL-1 had a crew of seven with all of its engines mounted level with the fuselage. The undercarriage consisted of ten wheels, including two wheels mounted towards the front of the aircraft (to prevent a nose-over on takeoff) and a tail skid. Components of the aircraft were assembled together to begin flight testing at Wilbur Wright Field. Final cost of the XNBL-1 project was $525,000, not including a $700,000 hangar to house the airplane.

Testing

Although capable of carrying a 5,000 lb (2,268 kg) bomb load, 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. A fully-loaded XNBL-1 had a range of only about 170 miles (273.59 km) with a top speed of 96 mph. In contrast, the "short-range" Martin NBS-1 had a range of about 450 miles (724.20 km) and could carry a 2,000 lb (907.18 kg) at the same speed. On a flight from Dayton, Ohio to Washington, DC, the Barling Bomber failed to fly over the Appalachian Mountains and had to turn around.

File:WITTEMAN-LEWIS XNBL-1 USAF.JPG

XNBL-1.

Although the XNBL-1 was not put into production, it had advanced features such as aluminium fuselage components, adjustable multi-wheel undercarriage, separate compartments for crew, a flight engineer, electrical instruments and advanced engine controls. One unusual feature was variable-incidence tailplane, which could be adjusted in flight using a lever in the cockpit. The XNBL-1 was the largest aircraft in the United States until the Boeing XB-15 in 1935.

Frequently characterized as "Mitchell’s Folly" (after Brig.-Gen. William L. Mitchell, who had championed the project), later in the decade, the aircraft had been disassembled by Air Service personnel and stored at Wright Field. After lying in disrepair for years, the Barling was quietly scrapped in 1928 at the order of General Henry H. Arnold to avoid a public outcry "over the million-dollar waste of taxpayer's money."

Specifications

General characteristics

• Crew: Seven (two pilots, five gunners)
• Length: 65 ft (19.81 m)
• Wingspan: 120 ft (36.58 m)
• Height: 27 ft (8.23 m)
• Empty weight: 27,132 lb (1,242 kg)
• Loaded weight: 42,569 lb (19,309 kg)
• Powerplant: 6× Liberty L-12A , 420 hp (313 kW) each

Performance

• Maximum speed: 95.5 mph (154 km/h)
• Cruise speed: 61 mph (100 km/h)
• Range: 170 miles (273.59 km) with full bomb load (varied by bomb load carried)
• Service ceiling: 7,725 ft (2344 m)

Armament

• Up to 5,000 lb (2268 kg) bombload
• 7 × 0.3 in (7.62 mm) machine guns

References

Notes

Bibliography

• Tilford, Earl H., Jr. "The Barling Bomber", in Aerospace Historian, June 1979, p.91-97.
• Winchester, Jim. The World's Worst Aircraft: From Pioneering Failures to Multimillion Dollar Disasters. London: Amber Books Ltd., 2005. ISBN 1-904687-34-2.

External links

• USAF Museum
• Maxwell AFB

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Witteman-Lewis XNBL".