Rubik R-31 Dupla
R-31 Dupla | |
---|---|
Role | Two-seat training glider |
National origin | Hungary |
Manufacturer | Begun by the designer, completed in the workshop of the National Civil Defence Association (MHSz), Budaörs |
Designer | Ernő Rubik |
First flight | 1983 |
Retired | 1986 |
Number built | 1 |
The Rubik R-31 Dupla (Double) was a Hungarian side-by-side seat training glider first flown in 1983. Disappointing performance and vibration problems prevented it going into production.
Design and development
Ernő Rubik had designed many gliders but by the 1980s had been retired a long time. His Dupla was intended as a light, low cost basic trainer to replace his widely used R-26 Góbé, which was coming to the end of its useful life having entered service in 1963. He began its construction in his own garage but later the Hungarian Defence League (Magyar Honvédelmi Szövetség or MHSz) offered help in their Budaörs workshops. It was first flown in 1983.[1]
The Dupla had a
The Dupla's forward fuselage was built around a tubular structure and covered in a mixture of light-metal and canvas. Pupil and instructor sat side by side, sharing some controls. There was a single,
The principal landing gear was a fixed monowheel aft of mid-chord. Forward of it, a skid protected the fuselage underside, assisted by a small tailskid on an extension of the fin below the fuselage.[1]
Operational history
Flying under only temporary certification, the Dupla made twenty-six flights, with a total of eight flight hours, between 1983 and 1986. Its performance was poorer than that of the Góbé it was intended to replace, its handling characteristics did not prepare students for gliders like the
Aircraft on display
- R-31 Dupla (prototype), Hungarian Technical and Transportation Museum.
Specifications
Data from Gabor,F (1988)[1]
General characteristics
- Crew: Two
- Length: 7.5 m (24 ft 7 in)
- Wingspan: 13.0 m (42 ft 8 in)
- Wing area: 15.0 m2 (161 sq ft)
- Aspect ratio: 11.3
- Empty weight: 188 kg (414 lb)
- Gross weight: 390 kg (860 lb)
- Dihedral: 3°
Performance
- Maximum speed: 160 km/h (99 mph, 86 kn) VNE; maximum speed with airbrakes open
- Stall speed: 55 km/h (34 mph, 30 kn)
- Maximum glide ratio: 22
- Rate of sink: 1.3 m/s (260 ft/min) approximately, minimum. at 72 km/h (45 mph; 39 kn)
- Maximum speed in rough air: 140 km/h (87 mph; 76 kn)
References