The Rolladen-Schneider LS7 is a high-performance Standard Class single-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. Sailplan ...

produced by

Rolladen-Schneider Flugzeugbau GmbH Rolladen-Schneider was a major glider manufacturer. The company originally made rolling doors and shutters and was run by Willi and Walter Schneider based in Egelsbach near Frankfurt, Germany. Walter was a keen glider pilot and recruited a sailpl ...

from 1988 to 1993.

Design and development

The LS7 was developed as the successor to the LS4, one of the most successful gliders ever produced. In a departure from the design philosophy of the LS4, Rolladen-Schneider set out to design the LS7 as an uncompromised competition machine, seeking the highest performance possible with the technology of the time. Designer Wolf Lemke specified a highly

laminar Laminar means "flat". Laminar may refer to: Terms in science and engineering: * Laminar electronics or organic electronics, a branch of material sciences dealing with electrically conductive polymers and small molecules * Laminar armour or "bande ...

wing profile and developed a high

aspect ratio The aspect ratio of a geometry, geometric shape is the ratio of its sizes in different dimensions. For example, the aspect ratio of a rectangle is the ratio of its longer side to its shorter side—the ratio of width to height, when the rectangl ...

wing. Carbon fibre was extensively used in the construction, along with

aramid Aramid fibers, short for aromatic polyamide, are a class of heat-resistant and strong synthetic fibers. They are used in aerospace and military applications, for ballistic-rated bulletproof vest, body armor cloth, fabric and ballistic composites ...

fibre, to ensure sufficient strength despite slender structural elements and increased loadings. The aileron drive bellcranks were entirely concealed within the wings, with only 30mm of usable height at the trailing edge. The LS7 prototype flew for the first time in the autumn of 1987, and serial production started in 1988. Winglets were introduced in 1991, yielding the LS7-WL. Many earlier LS7s were converted to this standard. Production ended in 1993 with a total of 164 aircraft built. The LS7 did not enjoy the commercial and sporting success its advanced features seemed to warrant. Its higher thermalling speeds proved to be a handicap in the gaggling environment typical of competition gliding. Other gliders designed at about the same time following a similar design philosophy also revealed non-classic low-speed behaviour, such as the ASW 24 and the DG-600. These gliders climb better in thermals when flown significantly above stall speed and achieve the best cross-country speeds at relatively moderate wing loadings, factors which were not fully understood at first. Although experience over the years has shown these gliders to be equal to any when flown by an expert hand, manufacturers nonetheless have returned to more conservative wing profiles and (mostly) lower aspect ratios. The LS7 was superseded by the LS8, which is currently manufactured at DG Flugzeugbau GmbH. The LS7 remains a much prized glider among private owners for its excellent performance and very nimble flight characteristics. The LS7 has more recently begun to achieve competition success in the Club Class, placing 1st in the 2019

European Gliding Championships The European Gliding Championships is a gliding competition held every two years. Gliding is a competitive sport and was even a demonstration sport at the 1936 Summer Olympics. It was due to become an official Olympic sport in the Helsinki Games ...

, Slovakia.

Design features

* Wings: spar and shell of foam / carbon reinforced plastic sandwich * Ailerons: synthetic foam /

reinforced plastic sandwich. Ailerons extend over fully half the wing span. * Horizontal stabilizer: sparless sandwich of carbon reinforced plastic * Elevator: carbon/aramid reinforced plastic * Automatic connections for ailerons, airbrakes, elevator and water ballast valves * Integral

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and

PET film BoPET (biaxially oriented polyethylene terephthalate) is a polyester film made from stretched polyethylene terephthalate (PET) and is used for its high tensile strength, chemical stability, dimensional stability, transparency reflectivity, and ...

seals on all control surface gaps. * Water ballast system: one unvented ballast bag per wing located before the spar, valve and dumping orifice on the lower wing shell by the wing root. Glass reinforced ballast tank installed in the tail fin for correction of

centre of gravity In physics, the center of mass of a distribution of mass in space (sometimes referred to as the barycenter or balance point) is the unique point at any given time where the weighted relative position of the distributed mass sums to zero. For a ...

shifts due to wing ballast.

Specifications

References

LS-Flugzeugbau website
*Milan J P, LS7 - Une valeur sûre, Vôl à Voile, 1997 *Thomas F, Fundamentals of Sailplane Design, College Park Press, 1999 *Simons M, Segelflugzeuge 1965-2000, Eqip, 2004
Sailplane Directory
{{Rolladen-Schneider aircraft 1980s German sailplanes Rolladen-Schneider aircraft Aircraft first flown in 1987 T-tail aircraft

Design and development

Design features

Specifications

See also

References