Schempp-Hirth Ventus

Ventus
Role	15 metre-class sailplane
National origin	Germany
Manufacturer	Schempp-Hirth
Designer	Klaus Holighaus
First flight	1980
Number built	ca. 611
Variants	Schempp-Hirth Ventus 2

The Schempp-Hirth Ventus is a sailplane produced during 1980-1994 by Schempp-Hirth, a German sailplane manufacturer.^[1] It was designed by Klaus Holighaus and replaced the Schempp-Hirth Mini-Nimbus. Schempp-Hirth manufactured 613 Ventus sailplanes.

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.

Variants

data from:Schempp-Hirth Flugzeugbau GmbH website^[2]

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^[3]

General characteristics

Crew: 1
Length: 6.58 m (21 ft 7 in)
Wingspan: 16.6 m (54 ft 6 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

200 km/h (110 kn; 120 mph) in rough air

180 km/h (97 kn; 110 mph) on aero-tow

150 km/h (81 kn; 93 mph) on winch launch

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)

	a	b	b/16.6	bT	c	cT	cM
Wing span	15 m (49 ft)	15 m (49 ft)	15 m (49 ft) / 16.6 m (54 ft)	15 m (49 ft) / 16.6 m (54 ft)	15 m (49 ft) / 16.6 m (54 ft) / 17.6 m (58 ft)	15 m (49 ft) / 16.6 m (54 ft) / 17.6 m (58 ft)	15 m (49 ft) / 16.6 m (54 ft) / 17.6 m (58 ft)
Aspect ratio	23.7	23.7	23.7 / 27.7	23.7 / 27.7	23.7 / 27.7 / 30.2	23.7 / 27.7 / 30.2	23.7 / 27.7 / 30.2
Length	6.35 m (20.8 ft)	6.58 m (21.6 ft)	6.58 m (21.6 ft)	6.58 m (21.6 ft)	6.58 m (21.6 ft)	6.58 m (21.6 ft)	6.58 m (21.6 ft)
Wing area	9.51 m² (102.4 sq ft)	9.51 m² (102.4 sq ft)	9.51 m² (102.4 sq ft) / 9.96 m² (107.2 sq ft)	9.51 m² (102.4 sq ft) / 9.96 m² (107.2 sq ft)	9.51 m² (102.4 sq ft) / 9.96 m² (107.2 sq ft) / 10.15 m² (109.3 sq ft)	9.51 m² (102.4 sq ft) / 9.96 m² (107.2 sq ft) / 10.15 m² (109.3 sq ft)	9.51 m² (102.4 sq ft) / 9.96 m² (107.2 sq ft) / 10.15 m² (109.3 sq ft)
Weight empty	240 kg (530 lb) approx.	240 kg (530 lb) approx.	243 kg (536 lb) approx.	240 kg (530 lb) approx. / 243 kg (536 lb) with sustainer removed	240 kg (530 lb) approx. / 243 kg (536 lb)	289 kg (637 lb)	300 kg (660 lb)
Max T/O weight	525 kg (1,157 lb)	525 kg (1,157 lb)	430 kg (950 lb)	525 kg (1,157 lb) / 500 kg (1,100 lb) with sustainer removed	525 kg (1,157 lb) / 500 kg (1,100 lb)	430 kg (950 lb)	430 kg (950 lb)
Max wing loading	55.2 kg/m² (11.3 lb/sq ft)	55.2 kg/m² (11.3 lb/sq ft)	43.2 kg/m² (8.8 lb/sq ft)	55.2 kg/m² (11.3 lb/sq ft) / 49.3 kg/m² (10.1 lb/sq ft) with sustainer removed	55.2 kg/m² (11.3 lb/sq ft) / 49.3 kg/m² (10.1 lb/sq ft)	42.4 kg/m² (8.7 lb/sq ft)	49.3 kg/m² (10.1 lb/sq ft)
Max Power loading	-	-	-	-	-	28.1 kg/kW (46.24 lb/hp)	9.62 kg/kW (15.8 lb/hp)
Best glide at 35 kg/m² (7.2 lb/sq ft)	43.5 at 105 km/h (57 kn; 65 mph)	43.5 at 105 km/h (57 kn; 65 mph)	46.5 at 95 km/h (51 kn; 59 mph)	-	43 / 49 at 105 km/h (57 kn; 65 mph)	-	48-49 at 105 km/h (57 kn; 65 mph)
Min sink at 75 km/h (40 kn; 47 mph)	0.58 m/s (114 ft/min)	0.58 m/s (114 ft/min)	0.59 m/s (116 ft/min)	-	-	-	0.68 m/s (134 ft/min) engine retracted
Stalling speed	65 km/h (35 kn; 40 mph)	65 km/h (35 kn; 40 mph)	64 km/h (35 kn; 40 mph)	-	-	-	75 km/h (40 kn; 47 mph) (minimum speed)
V_ne	250 km/h (130 kn; 160 mph)	250 km/h (130 kn; 160 mph)	250 km/h (130 kn; 160 mph)	-	270 km/h (150 kn; 170 mph)	-	-180 km/h (97 kn; 110 mph) power on / 270 km/h (150 kn; 170 mph) engine retracted
Cruise	-	-	-	130 km/h (70 kn; 81 mph)	-	-	140 km/h (76 kn; 87 mph)
Climb rate	-	-	-	0.633–1.133 m/s (124.6–223.0 ft/min)	-	-	2 m/s (390 ft/min)
Take-off run	-	-	-	-	-	-	280 m (920 ft) / 420 m (1,380 ft) to 15 m (49 ft)
Range	-	-	-	201 km (109 nmi; 125 mi) + (sawtooth)	-	-	500 km (270 nmi; 310 mi) (sawtooth) / 320 km (170 nmi; 200 mi) (level)
Endurance	-	-	-	-	-	-	2 hours

Notes

↑ "SCHEMPP-HIRTH FLUGZEUGBAU GmbH". sailplanedirectory.com. Retrieved 22 January 2015.
↑ "Ventus". schempp-hirth.com. Retrieved 22 January 2015.
↑ John W.R. Taylor, ed. (1988). Jane's All the World's Aircraft 1988-89. London: Jane's Information Group. pp. 630–632. ISBN 0-7106-0867-5.

External links

Wikimedia Commons has media related to Schempp-Hirth Ventus.

Schempp-Hirth glider types

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GRP construction	Arcus Discus Discus 2 Duo Discus Janus Nimbus Nimbus 2 Nimbus 3 Nimbus 4 Mini-Nimbus Open Cirrus Quintus Standard Cirrus Ventus Ventus-2

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