Designed by Rudolf Kaiser, the prototype Ka-1, which first flew in 1952, was constructed in Kaiser’s attic. The model was later produced by Schleicher. The Ka-1 has top surface spoilers for approach control. No landing wheel is fitted, takeoff normally being made with the glider sitting on its mainskid.
Wing span: 10 m / 32.8 ft Wing area: 9.9 sq.m / 106.6 sq.ft Empty Weight: 95 kg / 209 lb Payload: 100 kg / 221 lb Gross Weight: 195 kg / 430 lb L/DMax: 18 75 kph / 40 kt / 47 mph MinSink: 0.95 m/s / 3.12 fps / 1.85 kt Wing Load: 19.7 kg/sq.m / 4.04 lb/sq.ft Aspect ratio: 10.1 Airfoil: Go 549 mod. Seats: 1
The Condor was designed by Heini Dittmar with the advice and help of Atexander Lippisch and Dipl-lng Fritz Kramer; the Condor owed something to an earlier sailplane, the 19m (62ft 3.5in) span Fafnir. Dittmar built the prototype Condor in a workshop at Wasserkuppe in his spare time and it made its debut in the 1932 Rhon gliding contest, which it won; its very clean lines aroused considerable interest, and it went into series production.
Introduced in its original form in 1932, the single-seat Condor 1, the high-set gull wings were braced with V-struts and had strengthened leading edges. The Condor series was built from wood, with the wooden-framed wing covered in doped aircraft fabric. The landing gear was originally a dolly for take-off, with the aircraft landing on a fixed skid, although at least one was modified to use a fixed monowheel. The wings have balanced DFS-style dive brakes for glidepath control. The horizontal stabilizer is of an all-flying tail design.
Designed by Heini Dittmar at the end of 1931 as a performance glider using the Fafnir hull drawings and was built by him for 2000 working hours using materials from the RRG aeronautics department. The flight was performed by his brother Edgar just before the Rhön competition in 1932, where Heini Dittmar and Condor won the junior class in the practice competition.
Condor I
The Condor 2 and the IIA, developed in 1935, replaced strut bracing with a cantilever wing with a new wing section of reduced thickness/chord ratio on the outer parts of the wings, living an improved glide angle and lower rate of sink at higher speeds. This version set a new world distance record of 303 miles in 1935 and was a well-known type at prewar gliding contests. The Condor itself was of conventional wood and fabric construction, with very long span ailerons and a landing skid under the fuselage; no monowheel was fitted.
In February 1934 a Condor was taken to South America and, flown by Heini Dittmar, set a new world altitude record of 14,272ft for sailplanes, breaking the previous record by nearly 6,000ft. In 1935 one was flown to a new world distance record of 504 km (313 mi).
The Condor 3, which appeared in 1938 and was built by Schleicher, had a longer, slimmer fuselage and strengthened cantilever wings which now incorporated DFS air brakes.
After the war Heini Dittmar formed his own company, Mowe-Flugzeugbau Heini Dittmar, and there developed a tandem two-seater version, the Condor 4, which first flew in 1953 and was very similar to the Mk 3 apart from the second seat. The two-seat Condor IV was put into series production by Schleicher. The Condor IV has a 18.0 m (59.1 ft) span wing that employs a Goettingen 532 airfoil at the wing root, changing to a NACA 0012 section at the wing tip.
Condor IVs were flown in the 1952 World Gliding Championships held in Madrid, Spain. During that contest Ernst-Günther Haase set a new world record in the multi-place category for speed over a 100 km (62 mi) triangle of 80.9 km/h (50 mph).
Condor IV
Hans Luenger imported one Condor IV-2 to the United States in 1952. After the wooden fuselage was damaged, he and Merritt Zimmerman built a new design replacement from welded steel tube and covered it with doped fabric. The new fuselage included a fixed wheel for landing gear. This aircraft was removed from the US Federal Aviation Administration registry in 2007.
The Condor, also referred to as the Dittmar Condor, single and two-seat gliders were produced in small quantities before the Second World War, produced again between 1952 and 1955 by Alexander Schleicher GmbH & Co and also by Ferdinand Schmetz.
Some sources state that there were a total of 18 Condors constructed, while one other says that the total number is unknown, but includes at least 18 Condor IVs built under licence in Argentina.
Condor IV in the Deutsches Museum Flugwerft Schleissheim
Peter Reidel’s Condor La Falda was modified to have a strut-mounted power-egg, containing a Kroeber M4 driving a pusher propeller, attached to the centre-section. The intention was for the power-egg to be carried to the glider by the retrieve crew, fitted to the glider and the pilot to fly the glider back to home base without the need to de-rig and transport by trailer. In practice it was found to be impractical due to the complexity of the mounting, as well as time and effort required to mount the power-egg.
A small series was created by licensees Ferdinand Schmetz in Herzogenrath (five Condor IV / 2 with DFS brake tabs) and Alexander Schleicher (seven Condor IV / 3 with Schempp – Hirth brake tabs that extend up and down). Schleicher successfully received type certification from the Test Center for Aviation Equipment (PfL). Replicas were made in Argentina as Condor IV / 4.
However, some copies of the Condor IV were also used as test vehicles for new development; For example, flaps were attached to an example and tested by Hanna Reitsch. This copy is owned by Luftsportverein Wipperfürth. A Condor IV is located at the airport in Osnabrück Aviation Association in Achmer. More Condor IVs are on display at Schleissheim’s Airport and the German Glider Museum at Wasserkuppe. A Condor IV also flies in Anklam, it comes from an Argentine production (license Schleicher).
Condor I Initial strut-braced, single-seat version introduced in 1932. Span: 17.26 m Wing area: 16.20 m² Wing extension: 18.4 Length: 7.65 m Empty weight: 310 kg Wing load: 19.12 kg / m Glide ratio: 26 Crew: 1
Condor IA
Condor II Germany, 1932 Wingspan: 56.562 ft / 17.24 m Wing profile: Gö 532 Wing area: 16.20 m² Wing extension: 18.4 Length: 25.525 ft / 7.78 m Empty weight: 330 kg Wing load: 19.75 kg / m² Min descent: 0.65 m / s Glide ratio: 26 Crew: 1
Condor IIB Improved cantilever wing Seats: 1
Condor 3 Span: 56 ft 6.25 in / 17.24 m Length: 24 ft 11.25 in / 7.6 m Wing area: 174.4 sq.ft / 16.2 sq.m Aspect ratio: 15.0 Wing section: Gottingen 532 Wing extension: 15 Empty weight: 507 lb / 230 kg Max weight: 717 lb / 325 kg Water ballast: None Max wing loading: 20.06 kg/sq.m / 4.11 lb/sq.ft Max speed: 112 mph / 97 kt / 180 km/h Stalling speed: 27 kt / 50 km/h Min sinking speed: 2 ft/sec / 0.6 m/sec Best glide ratio: 28:1 Crew: 1
Condor IV Wing span: 18 m / 59.2 ft Wing area: 21.2 sq.m / 230 sq.ft Aspect ratio: 15.2 Airfoil: Go 532, NACA 0012 Empty Weight: 358 kg / 789 lb Payload: 202 kg / 445 lb Gross Weight: 560 kg / 1234 lb Wing Load: 26.4 kg/sq.m / 5.37 lb/sq.ft L/DMax: 31 80 kph / 43 kt / 50 mph MinSink: 0.70 m/s / 2.3 fps / 1.36 kt Seats: 2
Condor IV-2 Wingspan: 18.0 m (59 ft 1 in) Wing area: 21.2 m2 (228 sq ft) Aspect ratio: 15.2:1 Airfoil: Root: Goettingen 532, tip: NACA 0012 Empty weight: 440 kg (970 lb) Gross weight: 590 kg (1,300 lb) Maximum glide ratio: 30:1 at 80 km/h (50 mph) Rate of sink: 0.70 m/s (138 ft/min) at 69 km/h (43 mph) Wing loading: 28 kg/m2 (5.7 lb/sq ft) Crew: one Capacity: one passenger
Condor IV-3 Wingspan: 18.0 m Wing profile: Gö 532 (inside) / NACA 0012 (outside) Wing area: 21.2 m² Wing extension: 15.3 Length: 8.44 m Empty weight: 358 kg MTOW: 520 kg Wing load: 24.5 kg / m² Maximum speed: 60 km / h Min descent: 0.7 m / s Glide ratio: 31 at 80 km / h Crew: 2
The Rhonbussard, designed by Hans Jacobs as a high performance type capable of cross-country flights of 200 or 300km (124 to 186 miles), first flew in 1933, coming in performance between the Grunau Baby and the high performance ships of the time.
Of conventional wood and fabric construction the Rhonbussard has cantilever two-piece high-set wings with a single spar and a leading edge torsion box and, as on the Rhonadler, the wings are secured to the fuselage by two conical bolts, so enabling rigging to be done quickly and easily. It lacks any spoilers, airbrakes or flaps for approach control. The long-span ailerons are operated by push-rods.
The pilot sits in an open cockpit under the wing leading edge, with a widescreen for protection, and the short oval section fuselage has a main skid for landing plus a tailskid, take-offs being made on a jettisonable double wheel. The tailplane is mounted on top of the fuselage forward of the rudder. One feature, which led to some notoriety, was the requirement for the wings to be joined together at the roots before being presented to the fuselage for attachment.
About 1931 the glider manufacturer Alexander Schleicher went to Hans Jacobs, then at the RRG (Rhön-Rossitten Gesellschaft) on the Wasserkuppe, for glider design that, like the RRG Fafnir designed by Alexander Lippisch, was capable making long cross country by travelling quickly between thermals but could be put into series production making it cheaper to build. Jacobs responded with the Rhönadler (in English, Rhön eagle), ready for the 1932 Rhön competition. The following year both Jacobs and Lippisch had to transfer to the state owned DFS (Deutsche Forschungsanstalt Für Segelflug) at Darmstadt, where Jacobs continued to refine the Rhönbussard, hence the DFS Rhönadler name.
The Rhönadler was a wood framed aircraft with plywood and fabric covering. In plan its high wing wings were straight tapered with a torsion resting D-box form by ply skin ahead of the single spar. Aft of the spar the wings were fabric covered. The Rhönadler wing root used a version of the thick Göttingen 652 section, modified by a reduction of its high camber; further outboard this turned into the progressively lower camber Göttingen 535 and Clark Y airfoils. Dihedral was constant, to avoid the constructional complication of the Fafnir’s gull wing. The ailerons were very long, occupying more than half the span. Though neither the prototype nor later production aircraft came with spoilers or airbrakes such devices, opening above the wing, were often retro-fitted.
The Rhönadler’s fuselage was quite slender and entirely ply covered, including the fin, the balancing part of the rudder and a small tail bumper. On the original version, even the cockpit canopy was a ply structure, with small, unglazed apertures for vision. This was progressively modified with increasing glazing into the 1935 variant’s multi-framed conventional canopy. To avoid the wing root aerodynamic interference that the Fafnir’s gull wing was intended to avoid, the Rhönadler’s wing was mounted just above the fuselage on a low, narrow neck or pedestal which placed the leading edge level with the top of the canopy. The high aspect ratio, all-moving horizontal tail was of similar construction to the wing, with most of the taper on the trailing edge where there was a deep cut-out at the root. The tailplane was low set on the prototype but raised just above the dorsal fuselage line on production aircraft. The broad chord, balanced rudder was also fabric covered. Landings were made on a sprung skid under the forward fuselage.
The Rhonadler (or Rhon Eagle) first flew in 1932; at this time the techniques of long distance soaring flight were beginning to be explored in earnest by sailplane pilots, and distance covered rather than time spent airborne was what pilots were aiming to achieve. At the 1932 Rhön the Rhönadler, flown by Peter Riedel, did not win but impressed enough to go into series production as the Rhönadler 32, with the prototype’s wing span slightly shortened, its vertical tail leading edge smoothed by a shorter rudder balance and its tailplane raised. This sold well, though production numbers are uncertain. The 1935 version’s alterations included a fully enclosed transparent canopy. Schleicher built sixty-five of them, making it the top selling German high performance glider; several were exported. A measure of the popularity of the Rhönadler is the number at the 1935 Rhön competition, twenty-three out of sixty contestants.
Production was undertaken by Schleicher at Poppenhausen. Sixty-five Rhönadler 35 were built. In the 1980s a new Rhönadler was built from original plans and flown. It is now in the Wasserkuppe museum.
Variants:
Rhönadler Prototype. Competed in the 1932 Rhön event. 18 m (59 ft 1 in) span. Ply fairing over cockpit with small oval openings for vision.
Rhönadler 32 First production version, with raised tailplane and simplified fin and rudder. Span reduced by 542 mm (21.3 in). Transparencies at the front of the cockpit.
Rhönadler 35 Second production version with full cockpit transparencies.
Seeadler Flying boat version with hull, markedly gulled wings and underwing stabilizing floats.
Specifications:
DFS Rhonadler Length: 23.622 ft / 7.2 m Wingspan: 57.087 ft / 17.4 m Crew: 1
Schleicher Rhönadler Span: 57 ft 1 in / 17.4 m Length: 23 ft 7.5 in / 7.2 m Wing area: 193.8 sq ft / 18.0 sq.m Aspect ratio: 16.8 Wing section: Gottingen 652 Empty weight: 375 lb / 170 kg Max weight: 551 lb / 250 kg Water ballast: None Max wing loading: 13.89 kg/sq.m / 2.84 lb/sq.ft Max speed: 80.5 mph / 70 kt / 130 km/h Stalling speed: 27 kt / 50 km/h Min sinking speed: 2.5 ft/sec / 0.75 m/sec Best glide ratio: 20:1
Rhönadler 35 Length: 7.20 m (23 ft 7 in) Wingspan: 17.40 m (57 ft 1 in) Wing area: 18.0 sqm (194 sq ft) Aspect ratio: 16.8 Airfoil: Root: modified Göttingen 652; mid-span: Göttingen 535; tip: Clark Y Empty weight: 170 kg (375 lb) Gross weight: 250 kg (551 lb) Maximum speed: 130 km/h (81 mph; 70 kn) Stall speed: 50 km/h (31 mph; 27 kn) Maximum glide ratio: 20:1 Rate of sink: 0.75 m/s (148 ft/min) minimum Wing loading: 13.6 kg/sqm (2.8 lb/sq ft) Crew: One
The Open Class Quintur 23 m wingspan is a very thin, high aspect ratio wing, with a maximum of 250 liters of water ballast, allowing for a potential wing loading between 39 and 58 kg/m².
Lange Aviation and Professor Loek Boermans were involved in the conception and design of the wings, with nine exact interacting wing airfoils that provide laminar flow over 95% of the lower and 75% of the upper wing surfaces and are based on a super-elliptical wing geometry. The concept of the outer wing panel with winglets were from Professor Mark Maughmer.
Structural design, ballasting and the patented, extremely light control design were provided by Lange Aviation.
A self-launch optimized fuselage has been designed for the Quintus, providing not only aerodynamic improvements but also details such as bug wiper “garages”. A forward-opening canopy makes getting in and out comfortable. Cockpit blends in either visual carbon or carbon-kevlar hybrid fibre, Alcantara lining, and engraved flap position indicator.
The Quintur M engine start-up is straightforward and automatic. To engage the engine, the pilot only needs to switch on the ignition and press the start button once the engine has been fully extracted. The engine’s start setup is always optimized by a microprocessor to match the current environment.
After switching off the ignition on the Ilec engine control unit, the control unit automatically stops and fixes propeller in the correct upright position and the engine gets retracted.
A rudder-integrated tail wheel supports precise steering for taxiing.
Wing span: 23m / 75.46 ft Wing area: 14.7 m² / 158.23 ft² Aspect ratio: 36 Fuselage length: 7.82 m / 25.66 ft Empty weight: 500 kg / 1102 lb Max. all-up weight: 850 kg / 1874 lb Wing loading: 38.8 – 57.8 kg/m² / 7.95 – 11.84 lb/ft² Max. permitted speed: 270 km/h / 146 kts / 168 mph
The Arcus was developed using an all-new wing design with full-span flaperons mated to the “L” cockpit design, as used on the Duo Discus XL. Designed by Tilo Holighaus and Christoph Wannenmacher, the Arcus first flew on 7 April 2009 at the Hahnweide airfield.
The Schempp-Hirth Arcus is a flapped two-seat 20m racing class glider of all composite construction, with optional water ballast. This two seater is as agile as a single seater and equipped with flaps.
Schempp-Hirth Arcus T ZK-GUS
It is available as a pure glider, a sustainer version Arcus T using the retractable Oehler-Turbo (Solo 2350) engine, and as a self-launching glider Arcus M using the Binder (Solo 2625) powerplant system.
Type certificate: EASA Type Certificate Data Sheet EASA.A.532 Issue 04 dated 08 October 2014 – Arcus T approved 17 May 2011 – Arcus M approved 20 June 2013 – Arcus approved 31 July 2014
Arcus MCTOW 750 kg [1653 lb.] – with Water Ballast Max. No. of Seats: 2
Arcus T Engine: Solo 2350 D Propeller: OE-FL 5.110/83 av MCTOW 800 kg [1763 lb.] – with Water Ballast Max. No. of Seats: 2
Model: Arcus M Engine: Solo 2625-02 (modified per SB 4600-3) Propeller: Technoflug KS-1G-160-R-120 MCTOW 800 kg [1763 lb.] – with Water Ballast Max. No. of Seats: 2
The 15-meter Ventus (Latin for ‘wind’) designed by Holighaus, Schott, Treiber and Schuo, (not to be confused with the later completely redesigned Ventus 2) has all-carbon fiber wings. The Ventus high performance single-seater is the first of a new generation of racing and competition 15m Class sailplanes featuring carbon-fibre in their structures; the mid-set wings are specially designed to take full advantage of this material’s lightness and extra stiffness. The strength of this material permitted use of a very thin and more laminar airfoil developed by F.X. Wortmann, Dieter Althaus and Ventus designer Klaus Holighaus, thinner than previous Wortmann profiles. The stiffness of carbon fiber prevents wing twist at high speeds such as often occurs with fiberglass. A special characteristic of this new section is that at low-drag speeds, stall warning buffeting occurs when the angle of attack must increase over 10° before the stall itself actually occurs, this giving a previously unknown safety margin in narrow thermals, in ridge or mountain flying and in landing. The wing and its skin are made entirely of carbon-fibre, which gives increased torsional stiffness and reduces by over two-thirds the negative tip twist experienced with thin glassfibre wings, and the resulting lift penalties; the wing skin is made of specially developed extrafine-weave carbon cloth, and has high stiffness to maintain the wing profile.
The same new air brake/flap system as on the Nimbus 2C is featured, the air brakes being behind the 70% chord line outside the wing’s laminar flow area, and this system gives an unusually short and slow landing. The two-piece ailerons feature Grob elastic flap-type joints on the lower wing surfaces to make the aileron/wing joint gapless and reduce drag, while enabling the upper surface gap to be kept very small. Tail surfaces are similar to those of the Nimbus, with a fixed incidence tailplane and elevator.
The prototype Ventus first flew on 3 May 1980 and was offered with an A model for shorter pilots, and a slightly wider and longer B model. There are two fuselage sizes, the normal version (the Ventus B) being big enough for pilots from 5ft 9in to 6ft 5in tall, this fuselage being 24.75in wide, 32.75in high and 21ft 4.47in long. The smaller fuselage (the Ventus A) is designed so that pilots up to 5ft 9in tall will not feel ‘lost’ in a cockpit designed to accommodate six-footers, and is 21.25in wide x 29.5 in high x 20ft 9.5 in long; its smaller size results in a slight performance bonus.
In both versions the pilot sits under a one-piece sideways-hinging cockpit canopy which is easily jettisonable; the canopy frame is of carbon-fibre and there is provision for a variety of instrumentation. Both fuselage sizes have a steel mid-fuselage frame on which is mounted the retractable monowheel, the flap and aileron drives and the wing lift-pin sockets; this frame takes the stresses from the landing gear directly through to the wings, and there is also a tail bumper fairing under the fin. The rudder sizes are slightly different for each fuselage size, and there is provision for over 330lb of water ballast in integral fuselage tanks.The Ventus has trailing-edge combination flaps and dive brakes, and aileron control mixers which reduce aileron deflection when extreme positve or negative flap is selected.
The B model had optional 16.6 m. tip extensions, while the C model offered 15 m winglets tip extensions increasing the span to 16.6 or 17.6 m, and a 5 kg /11 lb fin ballast tank. Dick Johnson tested a modified Ventus A with 16.5 m. tip extensions to give a demonstrated best L/D of 50 at 78 kph/ 42 kt/ 48 mph and a minimum sink rate of 0.43 m/s/ 1.42 fps/ 0.84 kt.
Ventus B/16.6
The sustainer Ventus bT had 16.6 m wings and a retractable 15 kW/ 20 bhp Oehler Solo turbo engine.
Constant refinement was also the key for the success of the Racing Class glider Ventus which debuted in spring 1986 as the model Ventus-c (on request with wing tip extensions for 17,6 m wingspan). In 1986 Klaus Holighaus, sole owner and designer of Schempp-Hirth, displayed new 17.6m tips for the Ventus.
These tips are swept back, with a second stage sweep (backwards and upwards). Holighaus declared that they would add another 2.5 to the L/D taking it to 49:1.
The new improved Ventus had a new aileron control system, “two-story” Schempp-Hirth airbrakes, drag reducing wing-fuselage fairings, and automatic hook-up of all controls.
Production of this model was ceased in 1994 after over 600 examples were produced (including self launchers and turbos).
The cT had 17.6 m wings and a Solo engine uprated to 22 kW/ 30 bhp.
A Ventus won the 15 m class at the 1983 World Championships at Hobbs, NM, and others took 10 of the first 15 places. R.L. Robertson of Great Britain, along with others, won the world triangle distance record of 1,363 km./ 846.9 miles in 1986 in a Ventus A.
The Ventus 2, despite its names, is substantially changed from its similarly named predecessor. It has a complely new Discus planform wing and comes in a number of different configurations.
The unpowered sailplane comes in three different varieties, the short fuselage 15 m Ventus 2a, the larger fuselage 15 m -2b, and the convertible tip 2c (which has the larger -2b fuselage) with a choice of 15 m or 18 m outer wing panels.
On the 31.03.94, the first flight of the “new Ventus generation’ took to the air. A concept still realized by Klaus Holighaus and advanced with energy, but he however could not bring to conclusion as he lost his life in a flight accident on the 09.08.1994.
He had still flown the variants Ventus-2a and Ventus-2b and had also witnessed the double victory of the Ventus-2 at the European Championships in Rieti in 1994 as a testament to his wing shape concepts. His last design also followed on to win the World Championships in New Zealand as well as in France in 1997. The 18m version of the Ventus-2 which was designed by Klaus Holighaus was first flown on the 30th March 1995 by his son Tilo for the time. It is produced as the Ventus-2c, as the Ventus-2cT with the “Turbo” and as the self launcher Ventus-2cM.
The sustainer engined 2cT comes with 18 m span, while the self-launching 2cM has the 15 m or 18 m wingtip option with an empty weight of approximately 350 kg / 772 lb. The liquid cooled Solo engine remains in the fuselage when the mast mounted propeller is raised. This has folding blades which reduce the size of the cutout required in the fuselage to accommodate the mast. As a flapped sailplane, the 15 m versions comply with 15 m racing class at the 1995 World Championships at Omarama, New Zealand.
Until spring 1998, 100 examples were delivered. As of the summer of 1998, the self launcher was being produced with an even more powerful SOLO engine.
The World Championships were successful in Mafeking 2001, with a renewed title for the Ventus-2ax in the 15m class, a variant sporting a drag reduced tail section and Maughmer winglets. These modifications (which improved the flight characteristics at lower speeds and higher wing loadings) were carried through to the Ventus2-bx, along with a newly designed outer contour and cockpit area shape.
The Ventus-2cT won the 18m class at the FAI World Air Games in Lillo/Spain. Mid May 2002 saw the delivery of the first ballistic chute “total recovery system“ fitted to a Ventus-2bxR which was designed by the neighbouring company Glasfaser-Flugzeug-Service GmbH in Grabenstetten and tested in a Discus. 2002 saw the delivery of the 1000th Discus (all variants) as well as the completion of the 1000th Ventus (all variants).
In 2003 a fire broke out in one of the buildings delaying production by several months. Affected were the fuselage moulds for the new Ventus-2cxT (a structurally strengthened version with optimised tail unit, improved outer wings and Maughmer winglets for increased roll rate at even higher wing loadings). These changes, including strengthening in the cockpit area, have been incorporated into the Ventus-2cx glider and the motorglider Ventus-2cxM as standard equipment and have the title of “New Ventus Generation“.
The European Gliding Championships in Lithuania 2004 confirmed the performance of the new Schempp-Hirth aircraft, with the the double win of the Ventus-2cx, and in the racing class with the bronze title from Axel Horn in a Ventus-2ax (behind two Ventus-2a).
A one-off sailplane known as the Lentus, which consists of a Ventus A fuselage fitted with Nimbus C wings, was used for performance comparison trials with the Ventus.
Ventus a Span: 49 ft 2.5 in Length: 20 ft 9.5 in Wing area: 102.4 sqft Aspect ratio: 23.7 Empty weight: 474 lb Max weight: 949 lb Max speed: 155 mph Min sinking speed: 2.17 ft/sec at 9.2 lb/sq ft wing loading Best glide ratio: 44:1 at 74.6 mph
Ventus a Wing span: 16.6m
Ventus b Span 15 m / 49 ft 2.5 in Wing area 9.51 sq.m / 102.4 sqft Aspect ratio 23,7 Fuselage length 6.58 m / 21 ft 4.75 in Unloaded weight approx. 225 kg / 486 lb Gross weight 525 kg / 949 lb Wing loading 31,5-55,2 kg/sq.m Water ballast 168 lt Maximum speed: 250 km/h / 155 mph Maneuver speed 200 km/h Min sink: 0.58 m/s / 2.17 ft/sec at 9.2 lb/sq ft wing loading Best glide ratio: 44:1 at 74.6 mph
The Schempp-Hirth Standard Class Discus was the successor to the Standard Cirrus, and dominated numerous World Championships between 1985 and 1995 (6 world titles in succession). The Standard Class Discus A first flew in 1984 using the fuselage and tail unit of the original Ventus with a new unflapped wing. The wing planform is noteworthy as being the first production sailplane to have the now common distictive shape where the leading edge sweepback increases towards the tip, establishing a worldwide trend in wing planforms.
Approach control is by top surface double panel schempp- hirth airbrakes. There is a 5kg / 11 lb water ballast tank in the fin for trimming purposes when the main wing mounted ballast tanks are used.
The Discus B incorporates the longer fuselage (about 23 cm/ 9 in) and roomier cockpit of the Ventus B.
The sustainer engined Discus bT, which first flew in 1988, has a retractable mast mounted15kW/ 21 bhp Solo engine with a Oehler folding prop. The T (for Turbo) model incorporates an engine, with no starter, choke and throttle. It is started by wind-milling the multi-blade folding prop. Once started, the engine runs at full power until switched off and then is automatically retracted. Over 150 of the Discus bT were built. The turbo-drive system also equips a successor the Nimbus-4DM.
Whilst the production of the single seat Nimbus-3 had to be discontinued after a fire in one of the production halls, this enabled the production of the Racing Class glider Ventus to be increased, allowing the increase in demand for its motorized variant Ventus-bT to be satisfied.
The self-launching Discus bM has a Rotax engine in the fusealage (in co-operation with Walter Binder) with a retractable mast mounted prop and was manufactured only in small numbers.
The Discus won the first three places in the Standard Class at the 1985 World Championships at Rieti, Italy, 12 out of the first 15 at the 1987 Worlds at Benalla, Austria, and again the first three places at the 1989 Worlds at Wiener Neustadt, Austria. Up to 1995 the Discus won all first places in the world championships.
The Discus CS is built under license in the Czech Republic by Orlican. The winglets (WL) is an option that was developed for further improvement of the climb performance.
After approximately 570 copies weere manufactured in Kirchheim/Teck (including Discus bT and Discus CBM), the Discus A and Discus b production stopped now in favour of the Discus-2. The design Discus CS, identical in constructed with the Discus b, was produced by Schempp Hirth vyroba letadel, at Chocen, CR.
The Discus 2 airfoil is thin (about 14.5 percent), incorporating studies by K.H. Horstmann and Dr. Wuerz (wing) and Luc Boermans (tail). The 5″ wheel with a hydraulic brake keeps the fuselage far away from the ground. The tail and cockpit are completely new designs. Empty weight of the prototype is about 240 kg. There is a tail ballast tank.
During stalls in clean configuration (flaps and gear not extended) buffetings on the airspeed indicator begins at about 77 km/h IAS (vortices of the upper fuselage hitting the airspeed probe that was mounted on the vertical tail), followed by a slight vibration at about 73 km/h IAS. The stall ocurred at less than 70 km/h IAS, the airplane vibrating and the airspeed indicator trembling between 65 and 80 km/h.
The Duo-Discus was designed specifically by Klaus Holighaus for two seat high performance flight. With its wingspan of 20m, the two seat fixed profile glider first flew on the 11.03.1993 on the Hahnweide. Despite limited production opportunities, over 150 aircraft were already in service around the world by the end of 1997.
In April 1998, the maiden flight of the first prototype of the Discus 2, registrated D-6111, took place. In 1998 the Discus-2 gained first place in the Hahnweide competition and also National Championships in Germany and England. In late summer 1998, the 250th Discus-CS delievered from Chocen.
1999 brought the maiden flight of the “Duo-Discus-Turbo” and Gunther Stahl became the “Junior World Champion” in the Standard Class with a “Discus-2b”.
The Duo Discus was conceived as an advanced trainer with good cross country ability. It has a four piece unflapped wing with a modified Discus wing. The fuselage is derived from that of the two-place Janus. Approach control is by top surface airbrakes.
With the title of European Champion in all three classes, in 2000 two new motor gliders were announced. The Discus-2T, and the Nimbus-4M with an internal lying Solo 2625-02 engine as copied from the Nimbus-4DM.
The World Championships were successful in Mafeking 2001, with a renewed title for the Discus-2 and the Ventus-2ax in the 15m class, a variant sporting a drag reduced tail section and Maughmer winglets. These modifications (which improved the flight characteristics at lower speeds and higher wing loadings) were carried through to the Ventus2-bx, along with a newly designed outer contour and cockpit area shape.
Additionally, the Ventus-2cT won the 18m class at the FAI World Air Games in Lillo/Spain. Mid May 2002 saw the delivery of the first ballistic chute “total recovery system“ fitted to a Ventus-2bxR which was designed by the neighbouring company Glasfaser-Flugzeug-Service GmbH in Grabenstetten and tested in a Discus.
2002 saw the delivery of the 1000th Discus (all variants) as well as the completion of the 1000th Ventus (all variants).
The 18m Discus-2C, first flown on the 16.09.2004, integrates of the “Turbo“ sustainer and shorter outer panels, allowing the Discus-2C to be used in standard class competitions.
Discus b Span 15.0 m Wing area 10.58 sq.m Wing aspect ratio 21,3 Fuselage length 6.58 m Unloaded weight approx. 230 kg Gross weight 525 kg Wing loading 29.5-49.6 kg/sq.m Max water ballast 180 lt Maximum speed 250 km/h Maneuver speed 200 km/h Leastst sink approx. 0.59 m/s Best lift/drag ratio 43
The Nimbus 2’s performance had made it a leading contender in Open Class competition flying, in which it had twice won the World championships, and so there were obvious possibilities in a Standard Class version of this type with a shorter 15m span wing with camber-changing trailing edge flaps/air brakes and designed to meet the new FAI regulations for Standard Class 15-metre sailplanes. The Mini Nimbus (HS 7) of 1976 was the first of Klaus Holighaus for the FAI-15m class. A single-seat, 15 metre wingspan sailplane with a new wing with both dive brakes and flaps, series one manufacture started in 1977 with fibre-glass. The wings stem from the Glasflugel Mosquito as well as most of the mechanics. Equipped with a trim system in which the pilot adjusts trim according to their weight and sets the flaps for the desired flying speed.
Water ballast is carried in sealed tanks lying along the spar. All controls connect automatically as the flying surfaces are installed, and the trim lever needs to be set only once per flight; thereafter changes in flap setting (-7 to +10 degree) automatically cause trim compensation.
The HS-7 Mini-Nimbus, designed by Dipl-Ing Klaus Holighaus, first flew in prototype form on 18 September 1976, and a total of 200 had been ordered by February 1977; altogether 155 Mini-Nimbuses of all versions had been delivered by the beginning of 1980.
As with the Nimbus 2, the T tailplane was an all-moving surface on initial production aircraft, but from March 1978 a fixed incidence tailplane was offered as an option for customers, the type being known as the Mini-Nimbus B with this tailplane.
The Mini-Nimbus C is offered with either carbon-fibre wings and tailplane or those of glassfibre construction and the same new features as on the Nimbus 2C. Of the same glassfibre/foam sandwich construction as the Nimbus 2, the cantilever mid wings have flaps that incorporate the wing root fairings and glassfibre air brakes in the wing upper surface immediately ahead of them. The flaps can be selected to five positions between -7° and +10°, and when they are lowered the trim lever operates the all-moving tailplane at the same time so as to give an automatic flap/trim system. Up to 265lb of water ballast can be carried, or 419lb in the carbon-fibre-winged Mini-Nimbus C. The glassfibre fuselage shell is stiffened with bonded foam rings and has a central tubular steel framework like that of the Nimbus 2; the fin is integral with the fuselage and the tailplane is of glassfibre/foam sandwich. Landing gear consists of a manually-retractable rubber-sprung monowheel with a drum brake. The pilot sits under a large one-piece flush-fitting canopy in a semi-reclining position.
Schempp-Hirth SH-7 Mini-Nimbus C
The original version has an all-moving horizontal tail, but the C model is made with a fixed horizontal stabiliser, optional carbon fiber wings and tail (which reduce the empty weight by 20 kg /44 lb) and a modified trim system.
Serial introduction of carbon fiber was first included on the Nimbus-2C, Mini-Nimbus-C, Janus-C and Janus-CM.The “C” has a carbon fiber wing and horizontal tail unit. A rear edge turning flap (a combination of spoiler and curving flaps) is common to all models, which lends unusual short landing characteristics to the Mini Nimbus. The Mini Nimbus elevator trim overlaid by the curving flap and the retractable landing gear was manufactured from GRP.
After 159 were built, manufacturing switched to the Ventus in 1980.
Schempp Hirth Mini Nimbus Length: 21.03 ft / 6.41 m Wingspan: 49.213 ft / 15.0 m Aspect ratio: 23.00 Airfoil: Wortmann FX 67-K-1 50 Wing area: 106.133 sq.ft / 9.86 sq.m Max take off weight: 992.3 lb / 450.0 kg Weight empty: 518.2 lb / 235.0 kg Max. weight carried: 319.7 lb / 145.0 kg Water ballast: 265 lb Max. speed: 135 kts / 250 km/h Wing Load: 45.64kg/sq.m / 9.35lb/sq.ft Glide ratio: 42.0 at 106 kph / 57 kt / 66 mph MinSink: 0.58 m/s / 1.90 fps / 1.13 kt at 80 kph Crew: 1
Mini-Nimbus C (carbon-fibre wings) Span: 15.0 m / 49 ft 2.5 in Length: 6.41 m / 21 ft 0.5 in Height: 4 ft 4 in Wing area: 9.86 sq.m / 106.1 sq.ft Wing section: Wortmann FX-67-K-150 Aspect ratio: 23.0 Empty weight: 215 kg / 474 lb Max weight: 500 kg / 1,102 lb Water ballast: 190 kg / 419 lb Max wing loading: 51.0 kg/sq.m / 10.45 lb/sq.ft Max speed: 155 mph / 135 kt / 250 km/h Stalling speed: 33 kt / 61 km/h Max rough air speed: 135 kt / 250 km/h Min sinking speed: 0.53 m/sec / 1.74 ft/sec at 48.5 mph / 42 kt / 78 km/h Best glide ratio: 42:1 at 65 mph / 57 kt / 106 km/h
Design work on the Janus was begun by Dipl-lng Klaus Holighaus in 1969, was continued from early 1972 onwards and the prototype first flew in May 1974. Production began with the second aircraft, incorporating several improvements, in January 1975.
The Janus seats two in tandem with the rear seat occupant positioned near the center of gravity. The original Janus and Janus B (first built in 1978) models had an 18.2 m. wingspan, fixed landing gear and a gross weight of 621 kg / 1,370 lb. The Janus B became available to customers in March 1978, seating for two and provision is made for up to 200 lb of water ballast in the wings but use is not recommended unless lift is expected to exceed 3.3 ft/sec. The flaps adjust from -7 o to +10 o. The glider is fitted with airbrake and tail parachute. The Janus B this having a fixed incidence tailplane instead of the all-moving type previously fitted.
The Janus has a glassfibre monocoque fuselage with bonded in foam bulkheads, and this is similar to the Nimbus 2’s but the cockpit section is lengthened to accommodate the two pilots in tandem with dual controls under a hinged one-piece canopy. Landing gear consists of a non-retractable monowheel with a drum brake, and a nosewheel; there is also a bumper under the rear fuselage. The two-piece cantilever mid wings have 2° forward sweep on the leading edge, and are of glassfibre/foam sandwich construction, with glassfibre monocoque ailerons, flaps and Schempp-Hirth air brakes in the wing upper surfaces; the camber-changing flaps are operated between +12° and -7°. The tailplane is also of glassfibre/foam sandwich construction.
The Janus C first built in 1979 has a 20-meter span with carbon wings and a carbonfibre tailplane, seating for two, and competition-type performance. The Janus CM, with a 20-meter span, is a two-place motorglider with carbon wings and fully retractable engine. The Janus C incorporated carbon fiber components, retractable gear, and a gross weight of 700 kg./ 1,543 lb. Camber-changing flaps (+12 to -7 degree), top surface-only airbrakes and a tail drag chute provide options for approach control. In all versions a small fixed wheel between the main gear ant the nose allows strong braking without scraping the nose.
The Janus M prototype, D-KIBO, first flew in 1978 and is a motorised version with a 55hp Hirth 0-28 engine mounted on a pylon aft of the cockpit end retracting into the fuselage. Motorised versions are the Janus CM self-launcher with retractable mast mounted Rotax two cycle engine, and the sustainer Janus CT with a 15 kW/ 21 bhp Oehler Solo 2350 turbo engine.
The self-starting version, the JANUS cm, flew for the first time 1978 and to it in several dozen copies to all world was supplied, at first with an Hirth engine, later then with a Rotax engine type 535. One hundred examples of all versions of the Janus had been delivered by early 1980 plus three motorised Janus CMs.
The Royal Air Force acquired 2 Janus C’s for its air cadet program.
No. of aircraft built to 10/15/81 120 (all versions).
The Janus has set several speed and distance records for two-seaters, including a 100km triangular closed circuit speed of 88.8mph in Switzerland flown by Klaus Holighaus and U. Plarre on 15 August 1974, a women’s goal and return flight record of 339 miles in Italy in April 1976, flown by Adele Orsi and M. Monti, and further speed records over 100km, 300km and 500km triangular closed circuits in South Africa in November 1977.
In 1996 two variants were being built when the Janus was retired from production. The Janus Ce and/or Janus CT were both equipped with 20 m carbon fiber wings, absorbed horizontal tail unit, larger vertical stabilizer and more effective airs brake. Earlier designs had the GRP wing with 18,2 m span – however the JANUS von Anbeginn had curving flaps.
A French development of the Janus is the SCAP-Lanaverre SL-2 all-plastics sailplane created by SCAP-Societede Commercialisation Aeronautique du Plessis, SàRL and Lanaverre Industries, the latter building the Standard Cirrus under licence from Schempp-Hirth. First flown on 15 October 1977, the SL-2 differs from the Janus chiefly in having provision for 30.8 Imp gallons (140 litres) of water ballast in the wings and a fixed tailplane with elevators instead of a one-piece all-moving tailplane; a more comfortable cockpit for the two pilots is provided, with provision for back-type parachutes.
Janus Span: 59 ft 8.5 in / 18.2m Length: 28 ft 3.25 in / 8.62 m Height: 4 ft 9 in / 1.45 m Wing area: 178.5 sq.ft / 16.6 sq.m Aspect ratio: 19.97 Wing section: Wortmann FX-67-K-170/15 Empty weight: 370 kg / 816 lb Max weight: 1,366 lb / 620 kg Max ballast: 200 lb Water ballast: None Max wing loading: 37.4 kg/sq.m/ 7.66 lb/sq ft Vne: 119 kts / 220 km/h Max speed: 136 mph (in smooth air) Stall 10 deg flap: 38 kt / 67 km/h Max aero-tow speed: 105 mph Max rough air speed: 119 kt / 220 km/h Min sinking speed: 2.30 ft/sec / 0.61 m/sec at 56 mph / 40.5 kt / 75 km/h Best glide ratio: 39.5:1 at 68.5 mph / 59 kt / 95 km/h
Janus B Seats: 2 Length: 28.3 ft Height: 3.3 ft Wing span: 60 ft Wing area: 179 sq. ft Wing aspect ratio: 20 Max wt: 1366 lb Standard empty wt: 838 lb Max useful load: 528 lb Water ballast: 440 lb Wing loading: 7.6 lbs/sq.ft Min sink: 132 fpm @ 43 kt Max speed: 119 kt Stall speed: 35 kt Glide ratio: 39-1 @ 54 kt Rough air airspeed: 119 kt
Janus C Seats: 2 Length: 28.3 ft / 8.62 m Height: 3.28 ft Wingspan: 65.6 ft / 20.0 m Wing area: 187.3 sq.ft / 17.3 sq.m Wing aspect ration: 23 Max wt: 1543 lb Standard empty wt: 782 lb Max useful load: 761 lb Wing loading: 8.2 lbs/sq.ft Min sink: 118.1 fpm @ 49 kt Max speed: 135 kt Stall speed: 37.8 kt Glide ratio: 43-1 @ 59 kt
Janus CM Engine: 45 kW/ 60 bhp Rotax 535 C L/DMax: 43 110 kph / 59 kt / 68 mph MinSink: 0.60 m/s / 1.97 fps / 1.17 kt Wing span: 20 m / 65.6 ft Wing area: 17.4 sq.m / 187.3 sq.ft Empty Weight: 365 kg / 805 lb Payload: 345 kg / 761 lb Gross Weight: 700 kg / 1543 lb Wing Load: 40 kg/sq.m / 8.2 lb/sq.ft Water Ballast: 200 kg / 440 lb Aspect ratio: 23 Airfoil: Wormann FX-67-K-170 Seats: 2
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