The PZL Bielsko SZD-55 Nexus is a Standard Class
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. Sailplan ...
produced by
PZL Bielsko since 1988. It was built in direct competition with the
Schempp-Hirth Discus
The Schempp-Hirth Discus is a Standard Class glider designed by Schempp-Hirth. It was produced in Germany between 1984 and 1995 but has continued in production in the Czech Republic. It replaced the Standard Cirrus. It was designed by Klaus ...
. The SZD-55 is still in production with approximately 110 built.
Design and development
The SZD-55 is built of fiberglass and has an elliptical wing. It has top surface
Schempp-Hirth
Schempp-Hirth Flugzeugbau GmbH is a glider manufacturer based in Kirchheim unter Teck, Germany.
History
Martin Schempp founded his own company in Göppingen in 1935, with the assistance of Wolf Hirth.
The company was initially called "Sport ...
type airbrakes. The glider is reported to have pleasant handling and to be easy to assemble, with automatic control hookups. With an empty weight of about 215 kg, it is the lightest of the current standard class gliders and it's known for its excellent climbing and
thermal
A thermal column (or thermal) is a rising mass of buoyant air, a convective current in the atmosphere, that transfers heat energy vertically. Thermals are created by the uneven heating of Earth's surface from solar radiation, and are an example ...
ling characteristics. The SZD-55 has a cambered wing-section and performs well at lower speeds, yet when full with water ballast (it can take up to 200 liters) it is also suitable for higher cruising speeds.
The main designer of the SZD-55 was Tadeusz Łabuć. Since the mid-eighties, the best
glider in the
standard class was undoubtedly the German standard
Discus, whose excellent performance was attributed to its unusual triple trapeze wing shape. So it was the logical step to adopt a similar idea for use as the outline of the new construction: the elliptical contour of the wing
leading edge
The leading edge is the part of the wing that first contacts the air;Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 305. Aviation Supplies & Academics, 1997. alternatively it is the foremost edge of an airfoil sectio ...
. In 1987 construction of the two prototypes started, factory numbers X-144 (SP-P501) and X-145 (SP-P502). They first flew on 15.08.1988 and on 03.01.1989 piloted by January Roman.
Despite enormous difficulties in obtaining advanced materials (carbon fabric, kevlar) which meant that the glider had to be built with glass-epoxy laminates (already a relatively old technology at the time) the manufacturer managed to create a glider with an unladen weight of just over 200 kg. This meant that the
PZL Bielsko factory constructed a glider that was lighter than the ones constructed using modern materials(
carbon fiber
Carbon fiber-reinforced polymers (American English), carbon-fibre-reinforced polymers ( Commonwealth English), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon comp ...
and
Kevlar
Kevlar (para-aramid) is a strong, heat-resistant synthetic fiber, related to other aramids such as Nomex and Technora. Developed by Stephanie Kwolek at DuPont in 1965, the high-strength material was first used commercially in the early 1970s as ...
), thanks to innovative construction techniques.
[Polskie szybowce 1945-2011 - Problemy rozwoju - ] This technology was further improved during the designing and building of the
SZD-56 Diana.
Specifications
See also
References
Allstar SZD, the manufacturer of the SZD-55US Dealer of SZD SailplanesSZD-55 on sailplanedirectory.comSZD-55 Flight Test Evaluation by Richard Johnson
{{Polish gliders
1980s Polish sailplanes
SZD55
SZD aircraft
Aircraft first flown in 1988