Schempp Hirth Ventus

Design and Development

The decline in the cost of carbon fibre during the 1970s allowed sailplane designers to design large components from carbon-fibre reinforced plastic (CFRP). The use of carbon-fibre lay-ups, designed to reduce aero-elasticity of wings, has allowed CFRP gliders to be designed to cruise at much higher speeds than those with wings made from fibreglass (GFRP) or wood, as well as take advantage of thinner aerofoil sections. The Ventus has a 15 metre wingspan, using CFRP in its structure, complying with 15m Racing Class specifications. Extended wingtips can be fitted to increase the span to 16.6 metres for competition in the Open Class. The fuselage was also produced in two sizes to suit pilots of different heights - the Ventus A for short pilots and Ventus B with a longer and wider cockpit. Both Ventus A and Ventus B have a complex flap/brake arrangement similar to that of the Glasflügel Mosquito and the Mini-Nimbus, but the Ventus C reverted to conventional upper-surface air-brakes that are separate from the trailing-edge flaps.

Wingtip extensions could be fitted to the Ventus A and B to increase the wingspan to 16.6 m. Longer extensions could be fitted to the Ventus C to increase the span to 17.6m. Modified extensions with winglets are also available. Some Ventus Bs and Cs are equipped with a small sustaining engine ("turbo") and are designated with a T while some are equipped with a more powerful engine and are self-launching and are designated with an M.

The best measured glide ratio of a Ventus at 15 metres wingspan is 44:1, improving to 46:1 with the 16.6 metre tips, giving a creditable performance for the 1980s and 1990s. Ventus sailplanes won two World Gliding Championships, competing against the ASW 20 and later the LS6 in the 15m class. Whilst the Ventus A and B acquired reputations for unparalleled high-speed glide performance, the Ventus C introduced improvements in handling.

About 613 Ventus sailplanes were built before being replaced by the Schempp-Hirth Ventus 2 in 1995.

The Ventus 1 remains a competitive glider winning national level competitions. The ventus 1a is still being flown at the World Championship level in 2017.

Variants

data from:Schempp-Hirth Flugzeugbau GmbH website

Ventus A (15m / 16.6m)

The production standard 15m class Ventus with shorter and narrower cockpit.

Ventus B (15m / 16.6m)

Production aircraft with larger cockpit for larger pilot.

Ventus BT (15m / 16.6m)

The Ventus B with a retractable sustainer motor.

Ventus C (15m / 17.6m)

Later model with improved handling and air brakes separate from the trailing-edge flaps.

Ventus CT (15m / 17.6m)

The Ventus C with a retractable sustainer motor.

Ventus CM (15m / 17.6m)

The Ventus C with a retractable motor for self-launching.

Specifications (Ventus c)

Data from Jane's All the World's Aircraft 1988-89

General characteristics

Crew: 1

Length: 6.58 m (21 ft 7 in)

Wingspan: 17.6 m (57 ft 9 in) with extensions

Height: 1.27 m (4 ft 2 in)

Wing area: 9.96 m² (107.2 sq ft) with extensions

Aspect ratio: 27.7 with extensions

Airfoil: Wortmann/Holigaus/Althaus section

Empty weight: 243 kg (536 lb)

Max takeoff weight: 430 kg (948 lb)

Water ballast: 160 l (42 US gal; 35 imp gal)

Performance

Stall speed: 64 km/h (40 mph; 35 kn)

Never exceed speed: 270 km/h (168 mph; 146 kn) in smooth air

g limits: +5.3 -2.65

Maximum glide ratio: 46.5 at 95 km/h (51 kn; 59 mph)

Rate of sink: 0.59 m/s (116 ft/min) at 75 km/h (40 kn; 47 mph)

Wing loading: 43.2 kg/m² (8.8 lb/sq ft)