Roller shutter cutter LS1

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LS1
Roller shutter cutter LS1f
Type: Glider
Design country:

Germany Federal RepublicFederal Republic of Germany BR Germany

Manufacturer:

Rolladen Schneider Flugzeugbau

First flight:

1968

Production time:

1968 to 1977

Number of pieces:

464

The LS1 is a single-seat glider the club class with 15 m range and rigid airfoil . It was designed for the then standard class ( FAI club class ) as the first own design by Wolf Lemke . It was produced by the company Rolladen Schneider Flugzeugbau from 1968 to 1977 in nine variants (LS1-0, a, b, c, d, e, ef, f, f (45)) and revised several times.

development

An LS1c at the Hetzleser Berg airfield

The original design still had a detached hood and a cross tail on an aluminum tail support, which was to be obtained from Heinkel .

The built prototype LS1-V1 finally had a retracted hood and a T-tail unit on a tail unit tube made of plastic, but still an internal steel tube construction. The LS1-0 differed from the prototype by the change in the angle of incidence on the wing and the full GRP structure of the fuselage. By changing the setting angle, an improvement in rudder control was achieved. In the LS1-a, the rear-edge rotary brake flaps have been replaced by Schempp-Hirth brake flaps that work on both sides. Only minor changes were made to the aircraft on the LS1-b.

From LS1-c, a retractable landing gear and common Schempp-Hirth airbrakes were installed instead of the double-acting Schempp-Hirth airbrakes (LS1-a and LS1-b) and a 10% larger rudder was introduced. With the LS1-d, a 60-liter water ballast could be added to the wing for the first time, which also led to a rule change in the standard class of that time. Furthermore, the maximum take-off mass was increased to 341 kg.

The LS1-e was privately built by a roller shutter cutter employee under the direction of Wolf Lemke. It differs from the LS1-c only in the use of the horizontal stabilizer of the LS2 . The horizontal stabilizer of the LS1-f was used on the LS1-ef.

The line of development culminated in the LS1-f, which visually and ergonomically differed significantly from the previous versions by a new fuselage with a slimmer cockpit and one-piece hood. The cockpit of the LS1-f is quite narrow, but designed ergonomically. This fuselage was used externally largely unchanged from the LS6 and LS7 to the current models LS8 and LS10 . Furthermore, a new damped horizontal stabilizer and a now sprung retractable landing gear were installed. The setting angle of the wings in relation to the fuselage has also been adjusted. The outside of the wings remained the same, but changes in production resulted in better shape accuracy. Wood was no longer used in load-bearing components. All in all, the aerodynamic modifications led to even better flight characteristics, especially noticeably improved high-speed flight performance. The very large payload range of the LS1-f, which ranges from 60 to 110 kg in the cockpit, is also remarkable. The curb weight is also comparatively low at 230–240 kg.

The LS1-f (45) was built for the 1976 World Cup in Finland; the enlarged water bags mean that a surface load of up to 45 kg / m² is possible. Due to the increased maximum wing loading, the improved high-speed flight characteristics could be better exploited in strong thermals.

Production was discontinued in 1977 in favor of the LS3 racing class aircraft . The actual successor to the LS1 was the LS4 in 1980 , which, with more than 1000 units built, became the most successful standard class glider in plastic construction to date. The LS1 became known through numerous victories at national and international championships.

The current model supervisor has been offering a comprehensive performance enhancement set for the LS1-f since 2017. These planes are called -neo. The options offered for this are fuselage-wing transitions, aileron end caps and winglets.

Flight characteristics

In all variants, the LS1 is said to have extremely pleasant flight characteristics and good climbing performance in thermals. The f version also achieves improved gliding performance at high speeds. Compared to other models of its time, the LS1 is relatively sensitive to soiling of the wing surfaces, for example from hitting insects or raindrops. This is primarily due to the airfoil profile used, which is quite thick at 19.6% relative height. The versions with pendulum rudder require special attention in winch launch, since if the rudder is pushed too hard, the flow on the horizontal stabilizer can be interrupted. Due to the high thickness, an inexpensive, lightweight spar could be built without CFRP . In terms of its performance, the LS1f is comparable to patterns such as ASW 19 , Standard Cirrus , Jantar Standard , Hornet and Glaser-Dirks DG-100 .

Versions

LS1-V1
the prototype had an internal tubular steel construction; this was replaced in the series version by a complete GRP body (1 piece)
LS1-0
a retractable landing gear was retrofitted and the setting angle of the wings was increased, which led to an improvement in the rudder controls in flight (15 pieces)
LS1-a
For the rear edge rotary brake flaps, double-sided Schempp-Hirth brake flaps were installed (3 pieces)
LS1-b
the Schempp-Hirth brake flaps were only installed on the top of the wing 5 pieces
LS1-c
Change of the rudder set-up, the rudder was linked with control cables instead of control rods (198 pieces from LS1-c and LS1-d)
LS1-d
convertible from LS1-c, increased maximum take-off weight with water ballast in the wings (198 pieces from LS1-c and LS1-d)
LS1-e
Fuselage of the LS1-d with the damped horizontal stabilizer of the LS1-f (2 pieces)
LS1-ef
Fuselage and tail unit of the LS2 (1 piece)
LS1-f
Modified fuselage of the LS2 with folding hood, new damped horizontal stabilizer, improved high-speed flight performance due to adjusted setting angle of the wing (238 pieces)
LS1-f (45)
enlarged water bags for a surface load of up to 45 kg / m² (2 pieces)

Sporting successes

  • In 1968 Helmut Reichmann won the DSM in Oerlinghausen on the LS1-V1 (D-4723) ahead of Walter Schneider on the LS1-0 in the standard class .
  • 1970 Helmut Reichmann became world glider champion in the standard class with the LS1-c in Marfa , USA .
  • In 2005 Christoph Nacke became Junior World Champion (JWGC) in the club class in Husbands Bosworth, Great Britain .
  • In 2007 Gill Spreckley became the women's glider world champion in the club class in Romorantin , France .
  • In 2016 Jan Rothhardt became world champion in the club class with an LS1-d in Pociūnai , Lithuania .

Technical specifications

Parameter LS1-V1 LS1-0 to LS1-c LS1-d LS1-f LS1-f (45)
crew 1
length 6.90 m 7.20 m 6.80 m
span 15 m
Wing area 9.74 m²
profile Wortmann FX-66-S-196 modified
Elongation 23.10
Tail unit undamped T-tail dampened T-tail
Preparation mass 264 kg 200 kg 210 kg 230 kg
Payload 75-110 kg 60-110 kg
Water ballast - Max. 60 liters Max. 80 liters
Max. Takeoff mass 360 kg 312 kg 341 kg 390 kg 439 kg
Wing loading 36.9 kg / m² 30.8-35 kg / m² 29.7-40 kg / m² 33-45 kg / m²
Glide ratio 37 at 90 km / h 36 at 90 km / h 37 at 93 km / h
Slightest sinking 0.60 m / s at 77 km / h 0.63 m / s at 78 km / h 0.62 m / s at 72 km / h
Minimum speed 65-60 km / h 65 km / h
Top speed 200 km / h 220 km / h 240 250 km / h 270 km / h

Whereabouts

The prototype (LS1-V1 (D-4723)) has been exhibited in the German Glider Museum on the Wasserkuppe since 2002 .

See also

literature

Web links

Individual evidence

  1. ↑ Gerhard Marzinzik: Rolladen-Schneider - 20 years of gliders . In: aerokurier . No. 11 , 1988, pp. 1510-1519 .