Engineering:Burnelli UB-14

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UB-14
Burnelli UB-14 photo Le Pontentiel Aérien Mondial 1936.jpg
Role Civil transport
Manufacturer Burnelli
Designer Vincent Burnelli
First flight 1934
Number built 3
Developed into Burnelli CBY-3

The Burnelli UB-14, also known as the Cunliffe-Owen Clyde Clipper, was a 1930s United States prototype lifting-fuselage airliner designed and built by Vincent Burnelli.

Design and development

Following on from his earlier designs Vincent Burnelli designed a commercial transport version using the lifting-fuselage concept. Burnelli's designs were based on the idea that an airfoil-section fuselage would contribute to the lift generated. The Burnelli UB-14 first flew in 1934, the airfoil-section fuselage was the centre-section of the wing. The aircraft had twin tailbooms and a widespan tailplane and elevator fitted with twin fins and rudders. The UB-14 had retractable landing gear and was powered by two Pratt & Whitney radial engines. An enclosed cockpit for the crew of two was located on the centre wing's upper surface. The cabin held 14 to 18 passengers.

Operational history

The first prototype, UB-14, was destroyed in a 1935 accident attributed to faulty maintenance on the aileron control system.[1] Burnelli then designed and built an improved version, the UB-14B. A modified version of the UB-14B design was built under licence in the United Kingdom by Cunliffe-Owen Aircraft, powered by two Bristol Perseus XIVC radials as the Cunliffe-Owen OA-1.[2] A contemporary photo shows the mockup of the original UB-14B, to be built by Scottish Aviation before bankruptcy. This design was to have had streamline inline engines. The OA-1 used radial engines.

In September 1936, Burnelli applied to the CAA for approval to fly a transatlantic flight with Clyde Edward Pangborn as the selected pilot.[3]

The Perseus XIVc-powered Cunliffe-Owen O.A.1 in July 1939

The Cunliffe-Owen failed its airworthiness certification due to excessive takeoff run and poor workmanship. It was performance tested at the A&AEE Boscombe Down in 1939.[4]

After appropriate work, in June 1941 Jim Mollison and an Air Transport Auxiliary crew delivered Cunliffe-Owen OA-1 G-AFMB to Fort Lamy, Chad. The aircraft was fitted out as a personal transport for General De Gaulle. It was later abandoned at RAF Kabrit in Egypt, and burned during VJ-Day celebrations.[5] The one other aircraft landed in Vichy France en route to Fort Lamy[6]

Variants

  • UB-14 Prototype, powered by Pratt & Whitney engines. Built by Burnelli Company. Destroyed 13 January 1935, without injury to those aboard.
  • UB-14B Second prototype with modifications. Built by Burnelli Company.
  • UB-14B Third prototype, modified from second unit. Built by Cunliffe Owen Aircraft in United Kingdom.

Specifications (UB-14B)

Burnelli UB-14 3-view drawing from L'Aerophile February 1936

General characteristics

  • Crew: two
  • Capacity: 14–18 passengers
  • Length: 44 ft 0 in (13.41 m)
  • Wingspan: 71 ft 0 in (21.64 m)
  • Height: 10 ft 0 in (3.05 m)
  • Wing area: 686 sq ft (63.73 m2)
  • Empty weight: 9,200 lb (4,173 kg)
  • Gross weight: 17,500 lb (7,938 kg)
  • Powerplant: 2 × Pratt & Whitney Hornet radial piston engines , 750 hp (560 kW) each

Performance

  • Maximum speed: 210 mph (383 km/h, 180 kn)
  • Cruise speed: 205 mph (330 km/h, 178 kn)
  • Range: 1,240 mi (1,996 km, 1,080 nmi)
  • Service ceiling: 22,000 ft (6,705 m)

Airfoils:

  • Fuselage: NACA 4323
  • Exterior wing, root: NACA 2412
  • Exterior wing, tip: NACA 2409

[7]

See also

Related development

Aircraft of comparable role, configuration and era

References

Notes

  1. "About". Burnelli successor company. Retrieved: November 28, 2015.
  2. "Fast Air Liner To Compete In Atlantic Race." Popular Mechanics, May 1937.
  3. "Ocean hop planned in metal airplane." The Washington Post, September 17, 1936.
  4. Mason 2010, p. 242.
  5. Aeroplane Monthly June 2006 p.95 with two bw plates
  6. Joss, D.A. "Flying Wing" Recollection, Flight International, 13 May 1965, pp. 750–751.
  7. Flight magazine, 1936 / pg. 1591

Bibliography

  • The Illustrated Encyclopedia of Aircraft (Part Work 1982–1985). London: Orbis Publishing, 1986.
  • Mason, Tim. The Secret Years: Flight Testing at Boscombe Down, 1939–1945. Crowborough, UK: Hikoki Publications, 2010. ISBN:978-1-9021-0914-5.

External links