Wibault 220

Michel Wibault was one of the pioneers of all-metal aircraft, along with Hugo Junkers and Claudius Dornier.[1] The Wibault 220, designed for the night reconnaissance role and with a crew of three (hence the R.N.3 designation), had both metal structure and covering, the latter longitudinally corrugated for stiffness where required. Its high, cantilever wing had a rectangular plan centre-section and trapezoidal outer panels. The latter also tapered in section, mostly on the underside, providing a little dihedral.[2] High aspect ratio, unbalanced ailerons filled the outer panels' trailing edges. The wing was built around two І-section spars.[3] Like other Wibault aircraft built before the Wibault 280, the ribs projected through the wing surface, which was constructed from metal strips with turned up edges.[3][4]

The Wibault 220 was powered by two 450 hp (340 kW) Gnome-Rhône 9Ac Jupiter nine-cylinder radial engines, each wing-mounted under the outer centre-section. They were attached at three points on the front and rear spars by a system of duralumin plates and steel tubes and were enclosed in teardrop cowlings with their cylinder heads exposed for cooling.[2]

Its flat-sided fuselage was dural framed, with all sides covered in corrugated dural sheet. The upper- and undersides had rounded deckings. The nose was semi-cylindrical in plan and contained an open cockpit for the navigator, who was provided with a flexibly mounted pair of machine guns. The pilot was also in an open cockpit, which was built into the wing leading edge; the rear gunner/observer's position was a little behind the trailing edge, equipped with another pair of flexibly mounted guns. Its floor had an opening into which a reconnaissance camera could be fitted. The gunner also had access to a ventral gun position. Behind him the fuselage tapered slightly to a conventional, cantilever tail with its triangular tailplane mounted on top and carrying narrow chord elevators. The fin was also triangular, with a tall, trapezoidal rudder which extended to the keel.[3]

The Wibault 220 had fixed, conventional landing gear with its mainwheels on V-struts hinged to the lower fuselage frames. The wheels were positioned below the engines, to which they were connected by vertical Messier oleo legs so that the track was a generous 4.80 m (15 ft 9 in). The tailskid also had a Messier shock absorber and was steerable.[3]

The French Senate approved the order for two examples of the Wibault 220 in March 1930[5] and both were reported as under construction in April.[6] By late May 1930 one was being tested at Villacoublay[7] and by early June Raoul Ribière had made several flights.[8] After that, nothing more about the 220 appears in the French aviation journals.

Wibault 220 RN3 3-view drawing from Aero Digest October,1930

Data from L'Année aéronautique 1930-31[9] except where noted

General characteristics

• Crew: Three: pilot, navigator, gunner
• Length: 12 m (39 ft 4 in)
• Wingspan: 18.22 m (59 ft 9 in)
• Height: 4 m (13 ft 1 in)
• Wing area: 52.80 m² (568.3 sq ft)
• Empty weight: 2,481 kg (5,470 lb)
• Gross weight: 3,616 kg (7,972 lb)
• Fuel capacity: 735 L (162 imp gal; 194 US gal)[3]
• Powerplant: 2 × Gnome-Rhône 9Ac Jupiter [10] 9-cylinder air-cooled radial piston engines, 340 kW (450 hp) each
• Propellers: 2-bladed

Performance

• Maximum speed: 197 km/h (122 mph, 106 kn) at 3,000 m (9,800 ft) (all performance figures with full load)
• Range: 1,200 km (750 mi, 650 nmi) [10]
• Service ceiling: 5,850 m (19,190 ft) reached in 43 min
• Time to altitude: 10 min 34 sec to 3,000 m (9,800 ft)

Armament

• Guns: 5 × 7.7 mm (0.303 in) Lewis guns; 2 in nose, paired on flexible mount, 2 in dorsal cockpit, paired on flexible mount, 1 in a ventral mount. Some sources report a single Lewis gun in nose.[10]