Rolladen-Schneider LS8

The Rolladen-Schneider LS8 is a single-seat Planeur of Standard Class in 15 meters and 18 meters. Sailplane developed by Rolladen-Schneider and rentrat in production in 1995. Following the bankruptcy of Rolladen-Schneider, the production was taken again by DG Flugzeugbau.

History

In the middle of the years 1980, LS4 lost its position of favorite in the standard class, following the arrival of excellent the Discus manufactured by Schempp-Hirth. LS7 was not a really satisfactory substitute, which made necessary a new design.

The originator Wolf Lemke was skeptic, as for the utility to develop an entirely new wing. There was no guarantee that the efforts and the investments required would bring a real profit, like LS7, ASW 24 and DG-600 had clearly shown it. The tools available at the time defined in a random way the behavior of the profiles under one day the variable and varied conditions of vol.

The Sailplane LS6 of class race (15 meters) carried out astonishing results with the locked camber flaps, but FAI outclassed it in class 15 meters. After this event, Rolladen-Schneider modified LS6-c by removing the camber flaps, while giving the profile of wing with a chock of angle of incidence of zero degree, and by adding Winglet S. This prototype, still experimental, outclassed the standard sailplanes very last thing during the German championships at Neustadt-Glewe.

The LS8 finally left in 1994 after some improvements compared to the prototype, like a modification of the ailerons and an aerodynamic improvement due to the removal of the slits of the camber flaps.

Scores:

2nd, 4th, 5th with the championship of Gliding in Omarama in New Zealand in 1995.
1st, 2nd with the championship of Gliding to St Auban in France in 1997.
6 on 10th place with the championship of Gliding in Bayreuth in Germany in 1999.
3 first place with the championship of female Gliding in Lithuania in 2001

Much always regards it as the best standard sailplane of all its class.

Commercially, the LS8 was a success, which was due at the same time to its potential raised compared to competition, and with the soft and easy characteristics of flight. Appeared in the last, the versions with extensions of wings and a version “turbo” were developed. A total of 491 specimens all confused versions had been manufactured since the month of December 1995.

In spite of the business success of the LS8 the company did not thrive and after an economic and legal battle, the LS8 and all the other sailplanes of Rolladen-Schneider were taken again by the company DG Flugzeugbau, where the LS8 - with some changes on the level of landing, and the addition gear of the “Turbo” version - is always in production.

Dévelloppemnt of the Turbo version

The development of the version the “Turbo one” of power plant passed by several stages with the original prototype being conceived by Peter Wright (technology of engine of formula 1) with a configuration or the engine remained in the fuselage and the propeller left quickly via a courroi and a hydraulic system. The courroi passed inside an aerodynamic carbon fiber pylon. This arrangement while being admired considerably was found too complex and expensive to manufacture and a design much more conventional for the Turbo one was thereafter selected for the production by LS. The design of LS since was modified by DG after their aquisition of LS (Rolladen-Schneider) with control devices of engine of house. The LS8-t prototype (Turbo) of original (after some difficulties with the new payment of EASA to try to export the plane towards France) was converted again in more or less standard LS8-b.

General description

The LS8 is of a flexible and relatively preserving design with a high potential of future development. Although mainly conceived with characteristics for the standard class, it lent itself easily for evolved/moved with extensions of wings and a motorization.

aerodynamic Configuration: Winglet S is by défault on all the versions; The extensions of wings for porrté the scale with 18 meters are in option on certain versions.

Structure: Wings, Winglet S, ailerons and the drift are manufactured in a mixture of glass and carbon fiber; the depth is a mixture between Kevlar and carbon fiber. The version lengthened has reinforced member. The cockpit consists of several layer of glass fiber to resist at the time of crach.

Control device: depth conventional and horizontal stabilizer for the longitudinal order and of the air-brakes of the type Schempp-Hirth on the suction face of the wing, ailerons with large cord (50%) and depth equipped with a spring tab.

Balancing of the control surfaces: the system of warping of the ailerons is balanced with counterweights integrated in the wings. The ailerons of the extensions of wings are also balanced. The depth and the gouerne of direction are 100% balanced.

Sealing: all the orders are integrated in the fuselage and the wings. The connection between the ailerons and the wings is sealed off by Teflon band for limited the trail. The horizontal stabilizer and the rudder have joints in Teflon and of Mylar.

Gear landing: actuated via the pedals of direction (in version DG, the feeins are coupled with the order of the air-brakes).

Ballast: ballast integral with two tank by wing for the LS8-a version and the following version. A small ballast of tail in the rudder of a capacity from 3.5 to 12 liters for corrected the centering of the sailplane.

Turbo
: the alternative - T brings an innovating solution to the problem of “Turbo”. The reliable engine solo 2325 is joined to an engine of low diameter of “pallet” which sacrifices a little effectiveness of propulsion in exchange of a trail much weaker if the engine does not start. The hydraulic unit of extension allows the instantaneous exit. The two innovations return LS8-t one of the surest turbos available (the “turbo” version of DG has an electric system of sorite).

Versions

Rolladen-Schneider

LS8: Original version with the tanks of ballast of wing and dismountable drift of LS6-c, and a scale limited to 15 meter.

LS8-a: Version with a reinforced member and which integrates structural ballasts of wing.

LS8-18: like LS8-a with in more the ailerons balances and a ballast of structural tail. 2 possible configurations 15 or 18 meter.

LS8-b: like LS8-18. Structurally prepared (wings and fuselage) with the assembly of a “Turbo” engine.

LS8-t: Like LS8-b with “turbo”.

DG Flugzeugbau

After the transfer of the property, designations and the characteristics slightly changed.

LS8-a: Like preceding version LS8-A, exepté the reinforcement of the member.

LS8-s: corresponds to preceding version LS8-18, with a widened landing gear, the wings reinforced to obtain greater wing load and a weight maximum of 575kg in 18m of scale.

LS8-St: The “turbo” version differs from the LS8-t version in the addition as on LS8-s and the replacement of the hydraulic system of exit of the engine and the driving management system by a DEI-NT (calculator DG of control and management driving parameter)

Technical data

Sources

LS-Flugzeugbau website

Sailplane Directory

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