The Trener is a modified version of the LIBIS-18 single-seater Standard Class sailplane which first flew on 20 October 1964 and was designed by the Letalski Institut Branko Ivanus, Slovenija – LIBIS. Of wooden construction with cantilever shoulder mounted wings with tapered outer panels, the LIBIS-18 did not go into production.
The VTC Trener differs from it chiefly in having the all-moving tailplane mounted slightly higher on the sweptback fin and rudder, and an improved cockpit layout, the pilot sitting under a flush-fitting one-piece cockpit canopy. The Trener is also of all-wood construction, using beech and Swedish plywood, and has Wortmann wing sections giving a thickness/chord ratio of 18% at the root. The fuselage is a wooden monocoque with a non-retractable monowheel with a brake, andatailskid. An initial batch of 50 Treners is believed to have been ordered by the Yugoslav Aero Club, these being built by VTC at Vrsac.
Span: 49 ft 2.5 in Length: 22 ft 7.75 in Wing area: 139.6 sqft Aspect ratio: 17.35 Max speed: 136.5 mph (in smooth air) Max aero-tow speed: 93 mph Min sinking speed: 2.36 ft/sec at 48.5 mph Best glide ratio: 31:1 at 53 mph
This Yugoslav single-seater high performance Standard Class sailplane was designed by T.Dragovic and Z. Gabrijel, two young engineers at the Faculte des Siences Mathematiques in Belgrade, and the prototype, known as the Delfin 1, made its first flight in December 1963. It made its public debut at the 1965 World Championships at South Cerney in Gloucestershire, and went into production as the Delfin 2 at the Vrsac works of VTC – Vazduhoplovno Tehnicki Centar (Aeronautical Technical Centre).
The Mk 2, which first flew on 26 April 1965, differed from the prototype in having the plywood fuselage covering extended to cover the nose, a smaller sideways opening canopy, a rubber-sprung nose skid added and wooden instead of metal ailerons, and 27 of this version were built, four of which were later converted to Delfin 3s. The Delfin 2 achieved its first real competition success when it came 1st and 2nd in the Polish National Championships of 1966, no mean feat in view of the strength of opposition from the indigenous SZD designs.
The Delfin 3 first flew on 29 July 1968 and has a conventional tailplane instead of an all moving one, reduced fin sweepback and increased rudder area. It is of plywood-covered wooden construction; the cantilever shoulder wings have plywood-covered leading edges and fabric-covered rear portions, and wing tip ‘salmon’ fairings are fitted. There are metal Schempp-Hirth air brakes above and below the wing surfaces at 60% of the chord. The fuselage is a monocoque structure with a small cross-section made possible by putting the pilot in a semi-reclining position under a one-piece curved flush fitting cockpit canopy that opens sideways to starboard for entry and exit. The swept back fin is integral with the fuselage, and the fixed tailplane has a trim tab in the starboard elevator. Landing gear consists of a non-retractable unsprung monowheel with a mechanical brake and a rubber-sprung nose skid, plus a tail bumper.
Delfin 3 Span: 49 ft 2.5 in / 15.0 m Length: 22 ft 5.5 in / 6.85 m Height: 5 ft 3 in Wing area: 138 sqft / 12.82 sq.m Aspect ratio: 17.55 Wing section: NACA 633 618 Empty weight: 492 lb / 223 kg Max weight: 717 lb / 325 kg Water ballast: None Max wing loading 25.3 kg/sq.m / 5.18 lb/sq ft Max speed: 155 mph / 135 kt / 250 km/h (in smooth air) Max rough air speed: 78 kt / 145 km/h Stalling speed: 32.5 kt / 60 km/h Min sinking speed: 2.13 ft/sec / 0.65 m/sec at 46.5 mph / 40.5 kt / 75 km/h Best glide ratio: 31:1 at 54 mph / 47 kt / 87 km/h
This two-seater powered sailplane was developed jointly by VTC of Yugoslavia and Sigmund Flugtechnik of West Germany, under the design leadership of Dipl-lng Alfred Vogt and Dipl-lng Ivan Sostaric. The prototype, registered YU-M6009, made its maiden flight on 24 June 1972 in the hands of VTC test pilot A.Stanojevic; it was certificated in May 1973 and an initial order for 10 was placed by the end of that year. The SSV-17 is a low-wing monoplane of glassfibre sandwich construction with a conventional retractable undercarriage, seating two side-by-side; it resembles the Rumanian IS-28M2, but has a swept-back fin and rudder and a low-set tailplane; the fin spar is of steel tube. The wing has a light alloy main spar and Schempp-Hirth air brakes above and below, but there are no flaps. The fuselage is a semi-monocoque structure and the fuselage/wing centre section, 6ft 6%in wide, forms the cabin floor and also serves as the wing spar carry-through structure. The main wheels have coil spring shock-absorption and retract upwards into ‘knuckle’ fairings, remaining semi-exposed when retracted to minimise damage in a wheels-up landing. The tailwheel is fixed and steerable. The powerplant is a Franklin 2A-120-A two-cylinder horizontally-opposed engine of 60hp driving a two blade Hoffman propeller; but following the Franklin Engine Co’s cessation of engine manufacture the rights to produce and market this company’s range of air-cooled piston engines was acquired by Pezetel of Poland in 1975, to power such types as the Polish built PZL-110 Rallye. It is believed that only the initial batch of 10 SSV-17s was built.
Span: 55 ft 9.25 in Length: 23 ft 11.5 in Height: 9 ft 3.75 in Wing area: 199.1 sqft Aspect ratio: 15.65 Empty weight: 943 lb Max weight: 1,472 lb Max level speed: 155 mph (power on) Cruising speed: 99.5 mph (power on) Best glide ratio: 29:1 (unpowered) Min sinking speed: 2.79 ft/sec (unpowered) Take-off run: 820 ft Range: 497 miles
A glider built by Walton White Evans von Hemert. The machine was built in 1911 in a carpenter workshop in Amersfoort, Netherlands. Von Hemert (born 1894) was then 17 years of age. He made several flights with the glider, one of which was on 5 February 1911, as reported in the Dutch aviation magazine “De Luchtvaart”. The glider was towed by a car via a connecting line and the flight lasted about one minute at a height of around 10 meters. All of a sudden a gust of wind broke the left wing, crashing the machine. The wings were wrecked but the fuselage and the part where the pilot sat was intact. The rudder sported the identification “Aeroplane V. Hemert No. X”.
This single-seat waterborne biplane glider is designed to be towed in tethered flight behind a conventional motor boat. It was designed at the instigation of Volpar Inc. In February 1977 Volpar engaged Mr Percival H. Spencer, a pioneer pilot and amphibian designer, to design a small but fully manoeuvrable waterbased glider. This was to use modern plastics and foam materials for high strength and low cost, and to have simple controls that could be operated safely by an amateur or non-pilot.
Mr Spencer himself made the first flight of the prototype Drag-N-Fly, on 20 April 1977 (nearly 63 years after his first solo flight) and continued air and water trials have proved very satisfactory. Flight testing during 1978 resulted in the addition of a 1ft extension on each wing tip, to reduce the power requirements of the towing boat.
When in flight the tether can be disconnected by the pilot in an emergency, and will disconnect automatically if the glider tends to overrun the tow boat. The fuselage is hinged so that the Drag-N-Fly can be transported on a light road trailer without exceeding a width of 8ft 0in. The structure makes extensive use of stryrofoam and other lightweight materials; the strut-braced biplane wings are of constant chord and covered in glasscloth laminate, bonded with epoxy resin; there are spoilers on the outer panels of the upper wing. The wings themselves are built up of aerofoil shaped styrofoam blocks, with plywood spar caps bonded to styrofoam shear webs with epoxy resin. There are wooden blocks between the capstrips at each end to provide bolt attachments for joining the panels together. The fuselage and the twin floats which attach directly to the bottom of the lower wing are built up from plywood internal frames and bulkheads and are covered in polyester resin-bonded moulded glassfibre cloth laminate. The cantilever tail unit has a styrofoam core and glassfibre laminate covering; the vertical surfaces have wooden frame edges and the one-piece horizontal tail has plywood spar caps. The latter is hinged at the aft fuselage bulkhead and is statically balanced by means of a bob-weight; trim adjustment is by means of a bungee spring. There is a single open cockpit forward of the wings, an a water rudder is provided for control during towing, as well as the more conventional rudder.
Span: 17 ft 0 in Length: 15 ft 11 in Height: 5 ft 9 in Wing area: 113.0 sqft Aspect ratio: 2.56 Empty weight: 225 lb Max weight : 425 lb Max speed: 75 mph (in smooth air) Required take-off speed: 40 mph
The VJ-10 high-performance sailplane, the first two-place, side-by-side sailplane, was purchased by the military for the assault glider training program as the TG-29 42-65553.
It was designed and built by Volmer Jensen while at Bowlus, in 1939.
Jim Martin contracted Volmer Jensen to design and built him a glider for contest flying just before the Second World War.
The aircraft was constructed with a wooden structure and covered in doped aircraft fabric covering. The cantilever gull-style wing employed a NACA 4400 series airfoil. The tail was a conventional low-tail design and featured strut-bracing. The M-1 was registered as an Experimental – Amateur-built aircraft and was not type certified.
Jensen completed the aircraft in 1939.
Martin flew the aircraft in a number of US Nationals, as did a later owner of the M-1, Emil Lehecka. While Lehecka owned it the aircraft picked up the nickname of the Whatsit. By the 1970s the aircraft was owned by Francis Kalinowsky and was based at the Circle X airport in Florida. At that time it was reportedly in good repair and was well maintained.
The aircraft was removed from the Federal Aviation Administration registry and its whereabouts are unknown.
M-1 Wingspan: 48 ft 0 in (14.63 m) Wing area: 180 sq ft (17 m2) Aspect ratio: 12.8:1 Airfoil: NACA 4400 series Empty weight: 438 lb (199 kg) Gross weight: 631 lb (286 kg) Maximum glide ratio: 28 at 50 mph (80 km/h) Rate of sink: 132 ft/min (0.67 m/s) at 40 mph (64 km/h) Crew: one
All Aero 