The design of the LS4 was influenced mainly by the experience Rolladen-Schneider had gained with the LS2 and LS3 flapped gliders. Wolf Lemke returned to a double-tapered wing planform, giving it a larger area comparatively to the LS1 and LS2, and enlarged all control surfaces: the ailerons were elongated and brought further inboard and the tailplane span was increased. The fuselage and vertical stabilizer were taken from the LS3 moulds. Other notable features of the design were the retractable landing gear, the centre of gravity tow release that retracts with landing gear, the heel-operated wheel brakes, the upper wing surface air brakes and the water ballast system with internal bags. The structure is entirely glass-reinforced plastic mostly with synthetic foam cores. The exterior coating, as with most composite gliders, is gelcoat, which protects the load-bearing composite from humidity and UV-radiation, and is thick enough to allow wing profiling, which is done by hand during the finishing stages of manufacturing to achieve the smoothness required for extensive laminar flow. A total of 1,048 were built until Rolladen-Schneider entered receivership in 2003. Variants LS4 The initial production version LS4-a featured larger water ballast bags allowing for an additional 15 l (3.96 US gal; 3.30 imp gal) of water to be carried in each wing. The landing gear system is strengthened by the addition of one extra set of shock absorption bumpers in order to handle the increased gross weight with a full water ballast load. LS4-b fin height increased by 0.11 m (4.3 in) to 1.43 m (4 ft 8 in). The -b fuselage is 0.13 m (5.1 in) shorter at 6.66 m (21.9 ft). The wing shells are made in carbon, control connections are automatic, the instrument panel tilts up with the canopy and it has an optional tail fin water ballast system. Never Exceed Speeds 270 km/h (170 mph, 150 kn) in smooth air 180 km/h (97 kn; 110 mph) in rough air 180 km/h (97 kn; 110 mph) on aero-tow 130 km/h (70 kn; 81 mph) on winch launch LS4-a 280 km/h (150 kn; 170 mph) in smooth air LS4-a 190 km/h (100 kn; 120 mph) in rough air LS4-a 190 km/h (100 kn; 120 mph) on aero-tow LS4-a 140 km/h (76 kn; 87 mph) on winch launch
