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The Akaflieg Braunschweig SB 14 is an 18 m (59 ft) Open-class sailplane designed and built in Germany in the early 2000s.
| SB 14 | |
|---|---|
| |
| The SB-14 at ILA Berlin 2008 | |
| Role | single seat sailplane |
| National origin | Germany |
| Manufacturer | Akaflieg Braunschweig |
| First flight | 17 January 2003 |
| Number built | 1 |
Design and development
editThe SB 14 was designed to minimalist principles, reducing wetted area and use of high speed aerofil sections in a high aspect-ratio wing. As an economy measure, the tail unit of the Schleicher ASH 26 was utilised. To improve performance of the wing in a wide range of conditions, the wing-tips have swept wing-lets, as well as turbulators forward of the flaps on the undersurface of the wings.[1]
The SB 14 is a shoulder-wing sailplane constructed from carbon-fibre composite materials. The wings are of very high aspect-ratio and incorporate full span flaperons with slots for when the flaps are extended. The fuselage follows contemporary design practice with a cockpit pod and slender rear fuselage terminating in a T-tail. The cross section of the fuselage has been minimised throughout, reducing wetted area and therefore minimising drag.[1]
Control is through conventional elevator and rudder with full span slotted flaperons on the wings and Schempp-Hirth airbrakes on the upper surfaces at about 1/3 span. The undercarriage is a conventional retractable mono-wheel main undercarriage with a steel tipped rubber block tail-skid under the fin.[1]
Flight testing, from 17 January 2003, revealed very promising performance, optimised with various aero-dynamic refinements.[1]
Specifications (SB-14 prelim flight testing performance figures)
editData from [1]
General characteristics
- Crew: 1
- Capacity: payload (pilot + equipmqnt) 96 kg (212 lb); Water ballast 160 kg (350 lb)
- Length: 6.95 m (22 ft 10 in)
- Wingspan: 18.00 m (59 ft 1 in)
- Height: 1.23 m (4 ft 0 in)
- Wing area: 10.84 m2 (116.7 sq ft)
- Aspect ratio: 29.89
- Airfoil: root: CA2-134 / 15V2; tip: CAJ1-134 / 18
- Empty weight: 285 kg (628 lb)
- Max takeoff weight: 541 kg (1,193 lb)
Performance
- Never exceed speed: 272 km/h (169 mph, 147 kn)
- Minimum speed: 70 km/h (43 mph; 38 kn)
- Maximum glide ratio: 50:1 (approx)
- Rate of sink: 0.5 m/s (98 ft/min)
- Wing loading: 33.9 kg/m2 (6.9 lb/sq ft) to 50 kg/m2 (10 lb/sq ft)
References
editExternal links
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