Wibault 3

The Wib 3, or Wib 3 C.1 (the C for Chasseur or fighter, 1 indicating single seat) was Wibault's response to a call from the Service Technique de l'Aéronautique (S.T.Aé, Technical Department of Aeronautics) for a high altitude fighter. This was required to have a top speed of 240 km/h (149 mph) at 7,000 metres (23,000 ft) and a service ceiling of 8,500 metres (27,900 ft); to achieve this performance at altitude, the specification called for a turbocharged engine.[2]

It was an all-metal aircraft in the contemporary sense, with a structure of duralumin but largely fabric covering. A parasol wing, with a cut-out in the trailing edge over the open cockpit, ensured the pilot a good all round view. The wing was straight edged with constant chord and was fitted with long span ailerons. It was braced to the lower fuselage on each side with a pair of parallel, faired struts to about half span.[1] The wing section to half span was moderately thick but thinned outboard, giving an overall maximum lift to drag ratio of almost 20.[1][2]

The Wib 3 was powered by a 224 kW (300 hp) Hispano-Suiza 8Fb upright water-cooled V-8 engine[2] with a Lamblin cylindrical radiator on each side of the fully enclosed cowling. A Rateau supercharger maintained power up to 4,600 metres (15,000 ft).[1] The fuselage was aluminium skinned from its nose to the cockpit; aft, it was fabric covered.[1] Its wire braced, almost triangular tailplane carried split elevators, the inner ends cropped to allow movement of the broad rudder. The Wib 3 had a fixed conventional undercarriage, with mainwheels on a rigid axle supported by a pair of V-struts mounted at the roots of the interplane struts. The axle was enclosed within an aerofoil shaped fairing which added 1.50 m² (16.15 sq ft) to the wing area.[2]

On its first flight early in 1923, the Rateau turbo-supercharger was not fitted, its development having been interrupted by repeated failures caused by the difficulty of producing suitable high temperature resistant alloys. As a result, it was cancelled by the (S.T.Aé). The Wib 3 continued its flight testing until the autumn of 1923, after which the high altitude specification was withdrawn.[2]

Wibault 3 C.1

Wibault 3 C.1 three view

Data from Green & Swanborough pp.595-6[2]

General characteristics

• Crew: One
• Length: 8.20 m (26 ft 11 in)
• Wingspan: 11.72 m (38 ft 5 in)
• Height: 3.04 m (10 ft 0 in)
• Wing area: 25.00 m² (269.1 sq ft)
• Empty weight: 994 kg (2,191 lb)
• Gross weight: 1,420 kg (3,131 lb)
• Fuel capacity: 227 kg (500 lb)[1]
• Powerplant: 1 × Hispano-Suiza 8Fb water-cooled V-8, supercharged, 220 kW (300 hp)
• Propellers: 2-bladed

Performance

• Maximum speed: 241 km/h (150 mph, 130 kn) at sea level
• Range: 850 km (530 mi, 460 nmi) at 5,044 m (16,550 ft)[1]
• Endurance: 3.0 hr
• Service ceiling: 7,000 m (23,000 ft) service
• Wing loading: 53 kg/m² (10.8 lb/sq ft) [1]
• Power/mass: 160 W/kg (0.097 hp/lb) from Flight,[1] who give a power loading of 10.3 lb/hp

Armament

• Guns: 2×7.7 mm (0.303 in) synchronised Vickers machine guns, firing through propeller arc

• Bruner, Georges (1977). "Fighters a la Francaise, Part One". Air Enthusiast (3): 85–95. ISSN 0143-5450.

• "L'avion de Chasse Monoplan Wibault 3C1". L'Aérophile (in French): 138–141. 15 May 1923. Retrieved 30 August 2014.