Burnelli UB-14

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.

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 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 KabritinEgypt, and burned during VJ-Day celebrations.^[5] The one other aircraft landed in Vichy France en route to Fort Lamy^[6]

• 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.

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]

Related development

• Burnelli CBY-3
• Buscaylet-de Monge 7-5

Aircraft of comparable role, configuration, and era

• Kalinin K-7

• Photographs of the Burnelli UB-14 Archived 2012-02-18 at the Wayback Machine