Kellner-Béchereau 23

The Kellner-Béchereau 23 was a French two seat cabin touring aircraft, built in 1932. Its wing was constructed in a novel way. Only one was completed.

Design

The Kellner-Béchereau 23 was the first aircraft known as a Kellner-Béchereau (the company was founded in 1931), though the only example built (F-AKGH) was originally marked as the Béchereau 23.^[1]

It was a single engine cabin aircraft with an all-metal, three part cantilever wing constructed in a novel way. In place of spars, an approximately oval section, light metal tube, shaped around a wooden form which was then removed, provided both structural strength and formed the outer skin of the forward half of the wing. A more conventional lattice structure was attached to the rear of the tube and supported ailerons. The whole wing was then fabric covered.^[2][3]

In plan, the wing was approximately elliptical. The centre section, occupying about 20% of the span, was built into the fuselage and the outer panels tapered rapidly to pointed tips. The wings also tapered in section; the upper surface was horizontal but the lower sloped upwards, providing about 5° dihedral at the centreline. Their trailing edges were entirely filled with two-part, high aspect ratio ailerons.^[2]

Its flat-sided cross-section fuselage was built around four spruce longerons, transversely braced with steel tubes. They supported a light, fabric covered body formed with plywood frames and stringers. The 71 kW (95 hp) Salmson 7AC, a seven-cylinder radial engine, was in a pointed nose with its cylinders exposed for cooling. Its fuel tanks were in the wing centre-section. The tourer's cabin seated two in tandem under a long, multi-part, fully glazed canopy which ran from the leading edge to mid-chord, then blended without change in height into the upper fuselage. The cabin had two small baggage holds in the centre wing section, each providing 0.1125 m³ (3.97 cu ft) of space.^[2]

The empennage of the Kellner-Béchereau 23 was conventional, with a triangular tailplane mounted on the upper fuselage and carrying narrow, rounded elevators was wire braced to the blunted triangular fin which carried a curved and narrow unbalanced rudder. The tourer had a fixed tailwheel undercarriage with independent mainwheels on hinged V-struts from the fuselage underside and near-vertical sprung legs, with Béchereau shock absorbers, from the wings. The mainwheels, with a track of 2.80 m (9 ft 2 in), were equipped with independent brakes. At the rear the sprung tailwheel was free to castor.^[2]

Operational history

The date of the Kellner-Béchereau 23's first flight is not known but by early September 1932 it was sufficiently developed to begin its official tests with the S.T. Aé at Villacoublay, flown by Seitz.^[4] These were resumed in December.^[5] In September 1933 it was one of the eleven aircraft in the third annual, eight day Tour de France des avions prototypes.^[6]

Specifications

Data from Les Ailes July 1932

General characteristics

• Crew: One
• Capacity: One passenger
• Length: 8.74 m (28 ft 8 in)
• Wingspan: 14.0 m (45 ft 11 in)
• Height: 2.164 m (7 ft 1 in)
• Wing area: 23.10 m² (248.6 sq ft)
• Empty weight: 565 kg (1,246 lb)
• Gross weight: 860 kg (1,896 lb)
• Fuel capacity: 80 kg (180 lb)
• Powerplant: 1 × Salmson 7AC 7-cylinder air-cooled radial, 71 kW (95 hp)
• Propellers: 2-bladed Levasseur, 2.16 m (7 ft 1 in) diameter metal

Performance

• Maximum speed: 164 km/h (102 mph; 89 kn)
• Cruising speed: 123 km/h (76 mph; 66 kn)
• Range: 300 km (186 mi; 162 nmi)
• Service ceiling: 7,950 m (26,083 ft)
• Time to altitude: 45 min to 6,555 m (21,506 ft)
• Take-off distance: 145 m (476 ft)
• Landing distance: 140 m (460 ft)

References