Designed by Eugen Hanle for the 15 m racing class, the Mosquito is 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 Mosquito’s construction is generally similar to the Hornet, except for the ailerons, and up to 253lb of water ballast can be carried. The structure is fiberglass, with CFRP wing box spar and skin. The new flap/air brake system was developed jointly by Klaus Holighaus and Eugen Ha’nle; 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.

The prototype first flew in March 1976, it was the first type to go into production after the reorganisation of the Glasflűgel company under the name Holighaus & Hillenbrand GmbH & Co K.G following the death of its Director, Ing Eugen Ha’nle, on 21 September 1975. Dipl-lng Klaus Holighaus, the Director of Schempp-Hirth and Herr Hillenbrand of Glasflűgel formed the present company, continuing to market them under the Glasflűgel name.

A total of 90 Mosquitos had been delivered by January 1978.

Glasflűgel 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.

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 3.5in strip along the top of the fuselage under a Perspex fairing.

Gallery

Mosquito B
Wing span: 15 m / 49.2 ft
Wing area: 9.85 sq.m / 105.5 sq.ft
Length: 6.39 m / 21 ft 0 in
Height: 1.4 m / 4 ft 7 in
Empty Weight: 235 kg / 518 lb
Payload: 215 kg / 474 lb
Gross Weight: 450 kg / 992 lb
Wing Load: 45.68 kg/sq.m / 9.6 lb/sq.ft
Water Ballast: 120 kg / 265 lb
L/DMax: 41.2 at 71 mph / 59 kt / 110 km/h
Max speed (smooth air): 155 mph / 135 kt / 250 km/h
Stalling speed: 36 kt / 66 km /h
Max rough air speed: 135 kt / 250 km/h
Max aero-tow speed: 93 mph
MinSink: 0.58 m/s / 1.87 fps / 1.13 kt at 58.5mph / 43 kt / 80 km/h
Aspect ratio: 22.8
Airfoil: Wortmann FX-67-K-150
Seats: 1
No. Built: 300

In 1954 Eugen Hänle was then Assistant Professor Ulrich Hütter in a company engaged in the manufacture of large wind turbines for electricity production. The design of the 17 meter blades used fiber reinforced plastic glass.

With this experience, Eugen Hänle established Glasflügel in 1957, to produce helicopter rotor blades for Bölkow.

Meanwhile, Hütter had developed the H-30TS glider, derived from the H-30, with a modified fuselage to accommodate a small BMW turbojet and a new wing of 15 m with plastic flaps, but with glued aluminum sheet metal spar. Hänle then used the molds to produce wings in the Schempp-Hirth workshop. Two sets of wings with glass fiber spar were made. One of the wings was the first H-301 Libelle (or Dragonfly), other than the first Swiss Diamond, with its original 15 m wingspan.

Designed by Wolfgang Hutter and Eugen Hanle, the Libelle first flew on 6 March 1964 and became the first fiberglass sailplane to receive an U.S. ATC. 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. The two-piece cantilever mid wings are 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 Hütter air brakes, each 8 ft 2.5 in long, forward of the flaps. The wing leading edge has a compartment for water ballast, of which 110 lb 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.

In 1969 Soaring magazine readers voted the Libelle the World’s most beautiful sailplane. The H 301 Libelle has camber-changing flaps and was able to compete both in the Open Class and, with locked flaps, in the Standard Class.

A total of 111 Libelles had been built when production finally ceased in 1969.

Libelle 301
Wing span: 15 m / 49.2 ft
Wing area: 9.5 sq.m / 102.25 sq.ft
Aspect ratio: 23.6
Wing section: Hutter
Length: 6.2 m / 20 ft 4 in
Height: 2 ft 7.8 in (wheel up)
Empty Weight: 180 kg / 397 lb
Gross Weight: 300 kg / 661 lb
Payload: 120 kg / 264 lb
Water ballast: 50 kg / 110 lb
Max speed (smooth air): 155 mph / 135 kt / 250 km/h
Stalling speed: 35 kt / 65 km/h
Max aero-tow speed: 84 mph
Max rough air speed: 86.5 kt / 160 km/h
Wing Load: 31.25 kg/sq.m / 6.4 lb/sq.ft
L/DMax: 39 at 95 kph / 51 kt / 59 mph
MinSink: 0.55 m/s / 1.8 fps / 1.07 kt at 46.5mph / 40.5 kt / 75 km/h
Seats: 1

Designed by Eugene Hanle as a successor to the H 201 Standard Libelle, the Hornet is a derivative of the 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.

This Standard Class mid-wing design has 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 Hornet has trailing edge dive brakes operating well behind the laminar lift- producing area of the upper wing. The structure is fiberglass with a carbon wing box spar and skin, and Kevlar reinforced cockpit.

The unsprung monowheel has an internally expanding brake, and there is a fixed tailwheel.

The prototype made its first flight on 21 December 1974 and a total of 90 Hornets had been delivered by the summer of 1979.

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 375 lb (an additional 30 kg / 66 lb). 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.

Hornet
Wing span: 15.0 m / 49 ft 2.5 in
Length: 6.4 m / 21 ft 0 in
Height: 1.4 m / 4ft 7 in
Wing area: 9.80 sq.m / 105.5 sq ft
Wing section: Wortmann FX-67-K-150
Aspect ratio: 23.0
Empty weight: 227 kg / 500 lb
Max weight: 420 kg / 926 lb
Water ballast: 120 kg / 265 lb
Max wing loading: 42.9 kg/sq.m / 8.8 lb/sq ft
Max speed: 135 kt / 250 km/h
Stalling speed: 36 kt / 67 km/h
Min sinking speed: 0.60 m/sec / 1.97 ft/sec at 40.5 kt / 75 km/h
Best glide ratio: 38 at 56 kt / 103 km/h

Wing span: 15 m / 49.2 ft
Wing area: 9.8 sq.m / 105.5 sq.ft
Aspect ratio: 23
Airfoil: Wortmann FX 66-17
Length: 21 ft 0 in
Height: 4 ft 7 in
Empty Weight: 227 kg / 500 lb
Payload: 193 kg / 426 lb
Gross Weight: 420 kg / 926 lb
Wing Load: 42.86 kg/sq.m / 8.8 lb/sq.ft
Water Ballast: 170 kg / 375 lb
Max speed: 155 mph
Max aero-tow speed: 93 mph
L/DMax: 38 103 kph / 56 kt / 64 mph
Best glide ratio: 38:1 at 47mph
MinSink: 0.60 m/s / 1.96 fps / 1.16 kt at 47mph
Seats: 1
No. Built: 102

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 Eugen Hanle sought in the Club Libelle.

This was based on the Standard Libelle, differing from it principally in having new double-taper shoulder-mounted wings with a double taper, and a T-tail. The two-piece wings are of glassfibre reinforced plastic (GRP) foam section with spar flanges of parallel glassfibre and spar webs of GRP-balsa. The wings carry broad-span trailing edge flaps for approach control.

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 the Club model does not carry water ballast.

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.

Gallery

Wing span: 15m / 49 ft 2.5 in
Wing area: 9.8 sq.m / 105.5 sq.ft
Wing section: Wortmann FX-66-17A-11 -182
Aspect ratio: 23
Length: 6.4 m / 21 ft 0 in
Height: 1.4m / 4ft 7in
Empty Weight: 200 kg / 441 lb
Payload: 130 kg / 286 lb
Gross Weight: 330 kg / 727 lb
Wing Load: 33.67kg/sq.m / 6.9lb/sq.ft
Water Ballast: 0
Max speed: 124 mph / 108 kt / 200 km/h
Stalling speed: 32.5 kt / 60 km/h
L/DMax: 35.1 at 90 kph /49 kt / 56 mph
MinSink: 0.56 m/s / 1.84 fps / 1.09 kt at 42 mph / 36.5 kt / 67 km/h
Seats: 1