Glasflugel H-301 Libelle / H-201 Standard Libelle     Германия, 1964
Slingsby T.59 Kestrel     Великобритания, 1970
Страна: Германия
Год: 1964

Single-seat high-performance sailplane
M.Hardy. Gliders & Sailplanes of the world
Jane's Encyclopedia of Aviation

M.Hardy. Gliders & Sailplanes of the world

Glasflugel BS 1

  Regarded as having one of the highest performances of any sailplane when it was first rolled out at the end of 1962, the BS 1 was unusual in having a prone position for the pilot to keep the fuselage cross section as small as possible, as well as a braking parachute housed in the T-tail. It was designed by Bjorn Stender, who had worked on the SB-6 when a student at Akaflieg Braunschweig and who in 1962 had been asked to design and build a high performance sailplane by the South African pilot Helli Lasch. He set to work with only three other helpers and in spite of the BS 1's advanced nature they succeeded in finishing it by the end of 1962; it was of glassfibre construction - still a comparative novelty at that time - and also had camber changing flaps. After completing its flight tests the BS 1 broke the 300km (186 mile) international triangular speed record during the spring of 1963 and also had a number of competition successes. But following the tragic death of Bjorn Stender on a test flight in October 1963 the type was taken over by the Glasflugel company, who produced the modified BS 1B, which first flew on 24 May 1966. This featured a redesigned fuselage to provide a roomier cockpit, and a modified wing of increased span and a new Eppler 348 aerofoil section to give improved soaring capabilities in weak thermals. Glasflugel built a total of 18 BS 1Bs, one of these being supplied to the naturalist and sailplane pilot Sir Peter Scott.

Data: BS 1B
Span: 59 ft 0 1/2 in
Length: 24 ft 7 1/4 in
Height: 5 ft 0 1/2 in
Wing area: 151.7 sqft
Aspect ratio: 23.0
Empty weight :739 lb
Max weight: 1,014 lb
Max speed: 155 mph
Min sinking speed: 1.8 ft/sec at 53 mph
Best glide ratio: 44:1 at 59 mph

Glasflugel H 301 Libelle

  The H 301 Libelle (or Dragonfly) high performance single-seater is an all-glassfibre design developed jointly by Ing Eugen Hanle and Dipl-Ing W. Hutter from the V-tailed Hutter H-30 GFK; the latter had also participated in the design of the pre-war Schempp-Hirth Minimoa and a number of other successful gliders such as the H-17 and the H-28. The Libelle (the H in its designation stood for Hutter) made its first flight on 6 March 1964 and, although of Standard Class span, its camber-changing flaps and manually retractable monowheel put it into the Open Class; it could, however, be flown with flaps up and wheel locked down to conform with the then Standard Class rules. It was one of the first production glassfibre sailplanes and as such proved immediately popular, winning a number of National championships and breaking world speed and distance records; a total of 100 Libelles had been built when production finally ceased in 1969. Construction is similar to the Hutter H-30 GFK, the two-piece cantilever mid wings being glass-reinforced plastic/balsa sandwich structure with a single spar web and no ribs; the glassfibre spars are joined at the fuselage by a tongue/fork type of junction which was later to be adapted in a number of other sailplane designs. The mass-balanced ailerons are linked differentially with the flaps, and there are Hutter air brakes, each 8 ft 2 1/2 in long, forward of the flaps. The wing leading edge has a compartment for water ballast, of which 110lb can be carried. The fuselage is an all-glassfibre monocoque with balsa and synthetic foam and an integral fin; and the rest of the tail unit is of the same type of construction as the wings. The pilot sits in a semi-reclining position under a rearward-sliding one-piece canopy to reduce fuselage cross-section and hence drag, and a slightly higher canopy could be fitted if the customer so desired; there is provision for radio and oxygen, and the seat backrest and rudder pedals are adjustable in flight. The monowheel is mounted on a glassfibre shock absorber and has a brake; it is supplemented by a sprung tailskid or tailwheel.

Span: 49 ft 2 1/2 in
Length: 20 ft 4 in
Height: 2 ft 7 1/2 in (wheel up)
Wing area: 102.25 sqft
Aspect ratio: 23.6
Empty weight: 397 lb
Max weight: 661 Ib
Max speed: 155 mph (smooth air)
Max aero-tow speed: 84 mph
Min sinking speed: 1.8 ft/sec at 46.5 mph
Best glide ratio: 39:1 at 59 mph

Glasflugel H 201 Standard Libelle

  As its name implies, the Standard Libelle is a version of the popular Open Class H 301 Libelle with modifications to meet the Standard Class requirements; these consisted of removing the flaps and tail braking parachute, fitting a fixed instead of retractable monowheel and raising the height of the canopy. A new Wortmann wing section is featured and terminal velocity dive brakes are fitted. The canopy is unusual in having a catch that enables the front to be raised by 25mm in flight to provide a blast of ventilating air if required, instead of the more conventional small sliding panel used for this purpose. When the Standard Class rules were modified in 1970, a retractable monowheel was substituted for the fixed one. The Standard Libelle is of similar glassfibre construction to the H 301 Libelle, and likewise has provision for 110lb of water ballast in the wing leading edge. The prototype made its first flight in October 1967 and the Standard Libelle proved to be very popular, a total of 601 being built altogether. The type soon made its mark in contest flying; one flown by Per-Axel Persson of Sweden, winner of the 1948 World Championships, came second in the Standard Class at the 1968 World Championships at Leszno in Poland.
  The H 101 Salto is a version of the Standard Libelle developed by Frau Ursula Hanle, widow of Ing Eugen Hanle, the former Director of Glasflugel; the Salto (this word is German for loop) is produced by Start+Plug GmbH formed by Frau Hanle, and differs from the Standard Libelle largely in having a V-tail with an included angle of 99°. The Salto also owes something to the V-tailed Hutter H-30 GFK. Four flush-fitting air brakes repositioned on the wing trailing edges replace the more conventionally-sited air brakes of the Standard Libelle; the Salto's air brakes are hinged at their mid-points so that half the surface projects above the wing and half below. The Salto prototype first flew in March 1970 and 60 had been delivered by the spring of 1977; German type certification was granted on 28 April 1972 and the Salto has also been certificated by the FAA as well as Germany in the Normal and Aerobatic categories. The wing span is 13.6m (44ft 7 1/2 in) but a 15m (49ft 2 1/2 in) span wing can be fitted optionally for Normal category operation; the former wing has an area of 92.35sq ft and an aspect ratio of 21.8. The landing gear consists of a fixed monowheel with a fairing, and a tailskid, and the one-piece canopy is hinged to open sideways.

Data: H 201B
Span: 49 ft 2 1/2 in
Length: 20 ft 4 in
Height: 4 ft 4 in
Wing area: 105.5 sq ft
Aspect ratio: 23.0
Empty weight: 408 lb
Max weight: 772 lb
Max speed: 155 mph (smooth air)
Min sinking speed: 1.96 ft/sec at 46.5 mph
Best glide ratio: 38:1 at 53 mph

Glasflugel 205 Club Libelle

  The Libelle and Standard Libelle had proved to be so popular that the need was recognised for a development of these designs suitable for club training, especially for conversion training to the modern high performance glassfibre types in both Standard and Open Classes, and also for advanced cross-country soaring in preparation for Diamond C flights. Good handling characteristics and ease of landing away from base for the less experienced pilot were also necessary, and these were the qualities the designers sought in the Club Libelle. This was based on the Standard Libelle, differing from it principally in having new shoulder-mounted wings with a double taper, and a T-tail. The prototype Club Libelle made its first flight in September 1973 and a total of 171 had been built when production ended in August 1976. The two-piece wings are of glassfibre reinforced plastic (GRP) foam section with spar flanges of parallel glassfibre and spar webs of GRP-balsa, and the trailing edge flaps also act as air brakes. The fuselage is an all-glassfibre monocoque with no balsa or other type of sandwich, and there is a fixed monowheel with a brake. The cockpit is roomier than the Standard Libelle's, although the one-piece canopy is shorter, and, unlike the Libelle and Standard Libelle, the Club model does not carry water ballast.

Span: 49 ft 2 1/2 in
Length: 21 ft 0 in
Height: 4 ft 7 in
Wing area: 105.5 sq ft
Aspect ratio: 23.0
Empty weight: 441 Ib
Max weight: 727 lb
Max speed: 124 mph
Min sinking speed: 1.84 ft/sec at 42 mph
Best glide ratio: 35:1 at 56 mph

Glasflugel Kestrel 17

  The 17m span Kestrel high performance Open Class single-seater was designed to meet the demand for a successor to the Libelle variants with a longer-wing span and roomier cockpit; it was known originally as the 17m Libelle and has a new fuselage and wing profile and a T-tail. The prototype Kestrel first flew at Karlsruhe-Forchheim on 9 August 1968 and production deliveries began the following year, reaching a total of 129 by January 1978. The Kestrel 17 has several records to its credit, including the 100km closed circuit speed record of 102.74mph set by K. B. Briegleb of the USA on 18 July 1974 (since broken by an AS-W 17), and the ladies' 300km closed circuit speed record of 71.1mph set up by Susan Martin of Australia on 11 February 1972. The cantilever two-piece shoulder wings are of glassfibre and balsa and/or foam sandwich construction, with unidirectional glassfibre spar caps and glassfibre and balsa shear webs. High lift camber-changing flaps are featured which operate in conjunction with the ailerons between 8° and +12°, and can be lowered to 35° for a landing; both ailerons and flaps are partially mass-balanced. Up to 99lb of water ballast can be carried. There are flush fitting air brakes on the wing upper surfaces, and also a tail braking parachute which can be streamed for short-field landings. The monocoque fuselage is entirely of glassfibre (not sandwich) construction, and to cure a small airflow separation problem at the wing root fuselage junction at low speeds large wing root fillets were added to production aircraft; these were actually developed by Vickers-Slingsby, who built the Kestrel 17 under licence. The Italian firm of Glasfaser Italiana SrL has also built 25 Kestrel 17s, as well as 130 complete fuselage assemblies for the Kestrel. The Kestrel 17 tail unit is similar in construction to the wings, the fixed T-tail being secured by three attachments. Both the elevator and rudder are mass balanced. The monowheel is retractable, with an internally expanding brake, and there is an interchangeable tailwheel or tailskid.
  After Slingsby Aircraft Company Ltd had gone into liquidation in July 1969 the firm was reorganised as part of the Vickers Group, at first as Slingsby Sailplanes, later trading as Vickers-Slingsby and now as Slingsby Engineering Ltd. It was decided in September 1969 to produce a modern glassfibre design, and a licence to build the Kestrel was negotiated with Glasflugel. Construction of the first Slingsby-built T 59 Kestrel 17 began in March 1970, and it first flew on 15 August that year at Rufforth, Yorkshire; a total of 101 Kestrels had been built by Vickers-Slingsby by the end of 1974, plus two 22m span T 59H Kestrel 22s. Most of these have been 17m span versions, the first 19m span Kestrel, the T 59B, being flown by Mr G Burton in the 1970 World Championships in Texas. The next 19m version was the T 59C, which had a carbon-fibre main spar and first flew on 7 May 1971. This was followed by the T 59D of the same span, which first flew in July 1971, the extra span being in the form of 0.5m at each wing root and 0.5m at each wing tip. The T 59D also featured a larger fabric-covered rudder and an anti-balance tab in the elevator.

Data: Glasflugel Kestrel 17
Span: 55 ft 9 1/4 in
Length: 22 ft 0 1/2 in
Height: 5 ft 0 in
Wing area: 124.8 sq ft
Aspect ratio: 25.0
Empty weight: 574 lb
Max weight: 882 lb
Max speed: 155 mph
Min sinking speed: 1.80 ft/sec at 46 mph
Best glide ratio: 43:1 at 60.5 mph

Glasflugel 206 Hornet

  The Hornet is a derivative of the popular Club Libelle, differing from it chiefly in having an enlarged, longer two-piece flush-fitting cockpit canopy hinged at the front and rear, a retractable instead of fixed monowheel, and provision for up to 165lb of water ballast. The prototype made its first flight on 21 December 1974 and a total of 90 Hornets had been delivered by the summer of 1979. This Standard Class mid-wing design has, like the Club Libelle, a T-tail and the entire structure is of glassfibre monocoque, glassfibre/foam sandwich and glassfibre/balsa sandwich. The mid wing has a different incidence to improve high speed performance. Rotating air brake-type flaps and partially mass-balanced ailerons are on the wing trailing edges, and the elevator has a spring trim. The unsprung monowheel has an internally-expanding brake, and there is a fixed tailwheel. The Hornet C introduced in 1979 has a carbon-fibre torsion box to each wing, with carbon-fibre spar caps and a wing skin of carbon-fibre/plastic foam sandwich; the lighter weight of these wings allows the water ballast capacity to be increased to 375lb. The wing root fairings are modified and the C has the same one-piece cockpit canopy as the Glasflugel Mosquito. The prototype Hornet C first flew on 6 April 1979.

Span: 49 ft 2 1/2 in
Length: 21 ft 0 in
Height: 4 ft 7 in
Wing area: 105.5 sq ft
Aspect ratio: 23.0
Empty weight: 500 lb
Max weight: 926 lb
Max speed: 155 mph
Max aero-tow speed: 93 mph
Min sinking speed: 1.97 ft/sec at 47 mph
Best glide ratio: 38:1 at 47 mph

Glasflugel 303 Mosquito

  This Unrestricted 15m Class single-seater is, like the Hornet, a development of the Club Libelle and differs from the earlier Hornet chiefly in having carbon-fibre mass-balanced ailerons, and a new flap/spoiler/air brake system. Design of the Mosquito was started in the summer of 1975 and the prototype first flew in March 1976; a total of 90 Mosquitos had been delivered by January 1978. It was the first type to go into production after the reorganisation of the Glasflugel company under the name Holighaus & Hillenbrand GmbH & Co K.G following the death of its Director, Ing Eugen Hanle, on 21 September 1975. Dipl-Ing Klaus Holighaus, the Director of Schempp-Hirth and Herr Hillenbrand of Glasflugel formed the present company, which now has the world's largest sailplane production capacity, continuing to market them under the Glasflugel name. The Mosquito's construction is generally similar to the Hornet, except for the ailerons, and up to 253lb of water ballast can be carried. The new flap/air brake system was developed jointly by Klaus Holighaus and Eugen Hanle; conventional camber-changing trailing edge flaps act in conjunction with spoilers immediately ahead of them in the wing upper surface to act as a trailing edge air brake. The normal flap lever lowers the flaps and droops the ailerons in conjunction with them, while there is a second lever for the spoilers or brake flaps. As this is pulled, the spoilers start to open and further backward movement movement of this lever moves the flaps further downwards as well as opening the spoilers further. The latter can be opened or closed at any time like the more conventional Schempp-Hirth type air brakes fitted to other sailplanes. The tailplane at the top of the fin is fixed incidence, and the elevator has spring trim. The retractable unsprung monowheel has an internally expanding brake, and there is a fixed semi-recessed tailwheel. The one-piece canopy is raised by the pilot to hinge forward onto the nose tip for exit. Mr Humphrey Dimock, who runs the Royal Naval Gliding Club at Lee-on-Solent in Hampshire, has fitted a Mosquito with a 36-cell solar panel in the cockpit to charge a German Dry-Fit 14 volt battery at a rate of 0.46A when in sunlight; spare capacity generated by the panel can power blind-flying instruments if necessary and there is a cut-out to prevent overcharging. The panel weighs only a few ounces and is mounted directly in front of the pilot edge-on to his line of sight so as not to restrict visibility. Following the success of this panel Mr Dimock planned to fit 10 solar cells in a 5ft x 3 1/2 in strip along the top of the fuselage under a perspex fairing.
  Glasflugel began building the prototype of a new version, the Mosquito B, in September 1977. This differs from the standard Mosquito in having glassfibre reinforced plastic ailerons, no fuselage/wing root fairings, a reduced wing span and a tailplane of reduced span. Empty weight is reduced to 518lb but maximum weight and performance are the same as the standard Mosquito. First flight was on 24 March 1978 and about 90 Mosquito Bs had been delivered by January 1980.

Data: Mosquito
Span: 49 ft 2 1/4 in
Length: 21 ft 0 in
Height: 4 ft 7 in
Wing area: 105.5 sq ft
Aspect ratio: 22.8
Empty weight: 529 lb
Max weight: 992 lb
Max speed: 155 mph (smooth air)
Max aero-tow speed: 93 mph
Min sinking speed: 2.26 ft/sec at 58.5 mph
Best glide ratio: 42:1 at 71 mph

Glasflugel 304

  Intended to succeed the Mosquito B, the 15m span Glasflugel 304 single-seater is a new design very similar to the Mosquito, work on which began in the autumn of 1979 by a team under Martin Hansen. The prototype, D-9304, first flew on 10 May 1980. It employs a new 16.4% thickness/chord ratio wing profile developed by Akaflieg Braunschweig and extensively tested and refined on a Mosquito. Construction is of glassfibre, with no carbon-fibre employed, although the 304/17 (now known as the Glasflugel 402), which has detachable wing tips to give a span of 17m, has largely carbon-fibre wing tips. The fuselage is similar to the Mosquito's but with a more pointed nose; the monowheel is retractable. An unusual feature is that the instrument panel can be tipped up, together with the front-hinged upwards opening canopy, with which it is integral, to allow the pilot more unobstructed entry. Up to 253lb of water ballast can be carried. Production of the 304 started in the spring of 1981, and it will soon be followed by a carbon-fibre version, while there are plans for a motor glider variant.

Span: 304 49 ft 2 1/2 in
   402 55 ft 9 1/4 in
Length: 21 ft 2 in
Height: 4 ft 5 1/2 in
Wing area: 304 106.35 sq ft
   402 114 sqft
Aspect ratio: 304 22.78
   402 27.3
Empty weight: 518 lb
Max take-off weight: 992 lb
Max speed: 156 mph (smooth air)
Min sinking speed: 2.26 ft/sec at 58 mph
Best glide ratio: 43:1 at 72 mph

Glasflugel 604

  The 604 high performance single-seater is a 22m span version of the Kestrel 17, and in fact originated as a design study for a similar two-seater sailplane. The prototype made its first flight in April 1970, only four months after construction began, and took part in the 1970 World Gliding Championships at Marfa, Texas, taking sixth place; it later took second place in the 1974 World Championships at Waikerie, Australia. Only 10 604s were built but the type gained a number of competition successes and has set several world and national records, including one for speed over a 300km triangle, set by W. Neubert of West Germany in Kenya in March 1972 with a speed of 95.3mph, and the ladies' 100km triangular speed record of 79.1mph set by Adele Orsi of Italy in August 1975. The 604's wing consists of a centre section incorporating the fuselage top, and two outer panels joined to the centre section by the Hutter-Hanle method. The fuselage is 5ft 5in longer than the Kestrel 17's to give improved directional control with the longer span wing; the cockpit canopy, which is slightly shorter than the Kestrel's, is hinged to open upward and aft. There is a manually retractable monowheel with a brake, and a fixed tailwheel. Structurally the 604 is very similar to the Kestrel 17, and can carry up to 220lb of water ballast. Vickers-Slingsby has developed a similar 22m span version the Kestrel 17 known as the T 59H Kestrel 22 via the 19m span T 59D Kestrel 19.

Span: 72 ft 2 in
Length: 24 ft 11 1/4 in
Height: 5 ft 5 3/4 in
Wing area: 174.7 sqft
Aspect ratio: 29.8
Empty weight: 992 lb
Max weight: 1,433 lb
Max speed: 155 mph (smooth air)
Min sinking speed: 1.64 ft/sec at 45 mph
Best glide ratio: 49:1 at 61 mph

Vickers-Slingsby T 59H Kestrel 22 UK

  After putting the Glasflugel Kestrel 17 into production, Vickers-Slingsby (now Slingsby Engineering Ltd) began to pursue its own line of development of this Open Class single-seater, which resulted in the 19m span T59B, T59C and T59D. The D model was still further developed into the T59H of 22m (72ft 2 1/4in) span, the extra span consisting of two 1.5m stub wings inserted into the existing wing at the roots. The fuselage is similar to the Kestrel 17 up to just aft of the canopy, beyond which an additional section 29 1/2 in long is inserted which considerably reduced the 'waisting' of the earlier version. The fin and rudder area are increased by about 25%, although the tailplane is the same size as the Kestrel 17's; the rudder is lightened to prevent flutter by fabric-covered cut-out sections. Two prototype T59Hs were built, the first of these flying in 1974, but the new variant was found to suffer from a wing flutter at 140kts (161mph); Vickers-Slingsby had to recover the prototype T59H from the original customer who had bought it, while the flutter problem was investigated by the College of Aeronautics, where it was still being studied early in 1978. Like the T59C, the H has a carbon-fibre main spar and, apart from the longer fuselage and long-span four-piece wing, joined at the flap/aileron junction, it is structurally similar to the Kestrel 17 with the same cantilever T-tail, up to 220lb of water ballast can be carried. There are Schempp-Hirth air brakes in the upper and lower wing surfaces, and there is a retractable unsprung monowheel with a disc brake, plus a fixed tailwheel. The two T59H prototypes are known as the Kestrel 22 Series 1 and Series 2.

Data: T59H
Span: 72 ft 2 1/4 in
Length: 24 ft 9 1/4 in
Height: 6 ft 4 1/4 in
Wing area: 166.2 sqft
Aspect ratio: 31.35
Empty weight: 860 lb
Max weight: 1,453 lb
Max speed: 155 mph (in smooth air)
Max aero-tow speed: 93 mph
Min sinking speed: 1.57 ft/sec at 53 mph
Best glide ratio: 51.5:1 at 64.5 mph

Jane's Encyclopedia of Aviation

Glasflugel Kestrel, Hornet, Mosquito and Mosquito B (Germany)
   The Kestrel single-seat high-performance Open Class sailplane was known originally as the 17-metre Libelle and by the end of 1978 129 had been delivered. The Hornet is a derivative of the Club Libelle and is a single-seat Standard Class sailplane, 88 of which had been delivered by the end of 1978. The Mosquito is a single-seat 15-metre Contest Class sailplane, 100 of which had been delivered by January 1979. The Mosquito B (60 delivered) differs in having GRP ailerons, no fuselage/wing fairings, reduced wing span and slimmer horizontal tail surfaces.
Glasflugel Hutter 301 Dragonfly single-seat high-performance sailplane
Glasflugel H 301 Libelle.
Glasflugel H 201 Standard Libelle.
Glasflugel Standard Libelle single-seat high-performance sailplane
Glasflugel 205 Club Libelle single-seat Standard Class sailplane
Glasflugel 205 Club Libelle single-seat 15 metre sailplane
Glasflugel 205 Club Libelle.
Glasflugel 206 Hornet prototype 15 metre competition sailplane
Glasflugel Hornet.
Glasflugel Kestrel 17 metre single-seat high-performance sailplane
Glasflugel Kestrel 17.
Glasflugel 303 Mosquito.
Glasflugel Mosquito B.
Glasflugel 604 Kestrel single-seat high-performance Open Class sailplane, fifth production example
Slingsby T.59D 19 metre version of the Kestrel single-seat sailplane
19 metre version of the Glasflugel Kestrel, built by Slingsby as the T.59D
Start + Flug H 101 Salto single-seat sailplane, based on the Glasflugel Standard Libelle
Start + Flug H 101 Salto, based on the Glasflugel Standard Libelle
Glasflugel 701 side-by-side two-seat sailplane