Wibault 260
| Wibault 260 R.2 | |
|---|---|
| |
| Role | Long range reconnaissance aircraft |
| National origin | France |
| Manufacturer | Société des Avions Michel Wibault |
| First flight | S1 1930 |
| Number built | 2 |
The Wibault 260 R.2 was a contender for a French government contract for a long range, two seat reconnaissance aircraft, issued in 1928. There were eight prototypes in the 1931-2 contest and the Wibault was not selected for production.
Design
The French R.2 specification of 1928 called for an all-metal two seat reconnaissance aircraft, fast and with a rapid climb rate and large radius of action. It led to prototypes from eight manufacturers, the Amiot 130, Breguet 33, Latécoère 490, Les Mureaux 111, Nieuport-Delage Ni-D 580, Potez 37, Weymann WEL-80 and the Wibault 260. One of the terms of the specification required the manufacturers to use a Hispano-Suiza 12Nb water-cooled V-12 engine.[1][2]
The Wibault 260 was an all-metal monoplane with a parasol, cantilever wing. In plan the wing was largely trapezoidal out to blunt tips, with most of the sweep on the trailing edges, though it had a short span centre-section with an unswept leading edge and a deep cut-out in the trailing edge to improve the field of view from the cockpit. The thickness/chord ratio of the outer panels decreased progressively towards the tips. There was no dihedral. High aspect ratio ailerons filled the entire trailing edges. Wing and fuselage were joined by a pair of outward leaning, approximately N-form cabane struts between the outer ends of the centre-section and the upper fuselage. The wings were built around two spars and dural skinned.[3]
Its fuselage was constructed entirely in duralumin, with four longerons which defined its rectangular cross-section. Its water-cooled 480 kW (650 hp) Hispano-Suiza 12Nb upright V-12 engine was in the nose within a pointed engine cowling with bulges around the two cylinder blocks. Its shallow radiator curved around the underside of the forward fuselage at the rear of the engine. A 500 L (110 imp gal; 130 US gal) fuel tank was behind the fire wall. Aft, the pilot's cockpit was under the wing cut-out with a forward view under the wing and equipped with two fixed machine guns firing through the propeller disk. The observer/gunner's position was immediately behind the pilot and was equipped with photographic and radio equipment, together with two flexibly mounted machine guns.[3]
The empennage was conventional, with a triangular plan tailplane mounted near the top of the fuselage and braced on each side with a strut to the lower fuselage. Its angle of incidence could be adjusted in flight by the pilot. The elevators were narrow and rectangular apart from central cut-outs to allow operation of the trapezoidal rudder, which extended down to the keel and was mounted on a triangular fin.[3]
The Wibault 260 had fixed, conventional steel landing gear with a track of 2.60 m (8 ft 6 in), its wheels fitted with brakes. Upward sloping half-axles met centrally under the fuselage at the vertex of a transverse V-strut and, on each side, a faired, long displacement oleo leg and a faired drag strut, both from the lower fuselage longeron, carried the outer end of the axle. The tailskid also had an oleo strut.[3]
Development
The date of the Wibault 260's first flight is not known but it was flying by mid-1930.[4] In early November 1930 Ribière gave a "trés belle" (very fine) demonstration of it at Villacoublay.[5]
The S.T.I.Aé Concours des avions de grande reconnaissance (Long range reconnaissance aircraft competition) at Villacoublay began in April 1931[2] and, unusually, lasted about a year.[6] The French government had paid in March 1930 for two Wibault 260s to be built for the contest[7] but the winner was the ANF Les Mureaux 111,[6] so the Wibault did not go into production.
Specifications
Data from Les Ailes August 1930[3]
General characteristics
- Crew: Two
- Length: 10.38 m (34 ft 1 in)
- Wingspan: 14.939 m (49 ft 0 in)
- Height: 3.619 m (11 ft 10 in)
- Wing area: 30.345 m2 (326.63 sq ft)
- Empty weight: 1,800 kg (3,968 lb)
- Gross weight: 2,570 kg (5,666 lb)
- Fuel capacity: 500 L (110 imp gal; 130 US gal)
- Powerplant: 1 × Hispano-Suiza 12Nb water-cooled, upright V-12, 532 kW (713 hp) notional power 480 kW (650 hp)
- Propellers: 2-bladed
Performance
- Range: 900 km (560 mi, 490 nmi)
- Service ceiling: 5,000 m (16,000 ft) operational
Armament
- Two fixed, forward firing machine guns and two flexibly mounted machine guns
References
- ^ "Le concours des biplaces de grande reconnaissance". L'Aéronautique. 147: 275, 281–2. August 1931.
- ^ a b "Le concours des avions de grande reconnaissance". L'Aérophile. 39 (V): 145. 15 May 1931.
- ^ a b c d e Frachet, André (21 August 1930). "L'avion Michel Wibault". Les Ailes (479): 3.
- ^ "Le biplace de reconnaissance Wibault 260 R.2". L'Aéronautique. 134: 246. July 1930.
- ^ "A Villacoublay". Les Ailes (490): 12. 6 November 1930.
- ^ a b "Concours des avions de grande reconnaissance". Le Petit Parisen. 14 April 1932. p. 3. Retrieved 18 June 2016.
- ^ "Avions". Senat (124): 48. March 1930.