The LIBIS-17 was a two-seat

sailplane A glider or sailplane is a type of glider aircraft used in the leisure activity and sport of gliding (also called soaring). This unpowered aircraft can use naturally occurring currents of rising air in the atmosphere to gain altitude. Sailpla ...

for advanced glider training. It was built in

Yugoslavia Yugoslavia (; sh-Latn-Cyrl, separator=" / ", Jugoslavija, Југославија ; sl, Jugoslavija ; mk, Југославија ;; rup, Iugoslavia; hu, Jugoszlávia; rue, label=Pannonian Rusyn, Югославия, translit=Juhoslavija ...

(

Slovenia Slovenia ( ; sl, Slovenija ), officially the Republic of Slovenia (Slovene: , abbr.: ''RS''), is a country in Central Europe. It is bordered by Italy to the west, Austria to the north, Hungary to the northeast, Croatia to the southeast, an ...

) in the early 1960s and achieved production.

Design and development

The LIBIS-17, originally known as the LIBIS KB-17, was designed to provide tandem seat training in advanced gliding flight, including aerobatics and cloud flying, as well as solo experience to gold and silver C standard as a single seater. It had a

high wing A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...

of 5° dihedral, built around a single

spar SPAR, originally DESPAR, styled as DE SPAR, is a Dutch multinational that provides branding, supplies and support services for independently owned and operated food retail stores. It was founded in the Netherlands in 1932, by Adriaan van Well, ...

. The leading edge was a plywood

torsion box A torsion box consists of two thin layers of material (skins) on either side of a lightweight core, usually a grid of beams. It is designed to resist torsion under an applied load. A hollow core door is probably the most common example of a torsi ...

, supported by

Styrofoam Styrofoam is a trademarked brand of closed-cell extruded polystyrene foam (XPS), commonly called "Blue Board", manufactured as foam continuous building insulation board used in walls, roofs, and foundations as thermal insulation and water barrie ...

, and the rest of the wing was fabric covered. The

ailerons An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement around ...

were of the

Frise Frise may refer to: * Frise (department), the French name of Friesland as a ' of the First French Empire * Frise, Somme, a commune of the Somme department in France * Leslie Frise Leslie George Frise FRAeS (2 July 1895 – 26 September 1979) ...

type, wooden, foam filled and fabric covered. It had Hütter type plate spoilers just behind the spar. Both vertical and horizontal rear stabilizers were all-moving, single piece surfaces, fitted with

servo tabs __NOTOC__ A servo tab is a small hinged device installed on an aircraft control surface to assist the movement of the control surfaces. Introduced by the German firm Flettner, servo tabs were formerly known as Flettner tabs. Servo tabs are not ...

. Both were wooden structures, near-rectangular in shape, with Styrofoam filling. The fabric covered

fuselage The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraf ...

had a steel tube structure. The wing was mounted on a pylon which formed the rear of the cockpit. This seated two in tandem, under a framed, forward hinged, single piece

canopy Canopy may refer to: Plants * Canopy (biology), aboveground portion of plant community or crop (including forests) * Canopy (grape), aboveground portion of grapes Religion and ceremonies * Baldachin or canopy of state, typically placed over an ...

. A transparency in the wing leading edge assisted the upwards visibility from the rear seat. Aft of the wing the fuselage was slender and of rectangular cross-section. The LIBIS-17 had a bicycle undercarriage with a single mainwheel, fitted with brakes, and a smaller nosewheel. The prototype LIBIS-17 first flew in October 1961. The first production aircraft followed in June 1963 and 12 had been built by the following Spring, with production continuing. There is photographic evidence of a motorised version, with an engine and propeller on a mast above the wing.

Aircraft on display

A LIBIS-17 is on display in the

Museum of Aviation (Belgrade) The Aeronautical Museum Belgrade, formerly known as the Yugoslav Aeronautical Museum, is a museum located in Surčin, Belgrade, the capital of Serbia. Founded in 1957, the museum is located adjacent to Belgrade Nikola Tesla Airport. The current f ...

Specifications

References

{{LIBIS aircraft 1960s Yugoslav sailplanes