Roller shutter cutter LS4
|Roller shutter cutter LS4|
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The LS4 is a single-seat high-performance glider made by the German manufacturer Rolladen Schneider and was produced in series from 1980 to 2007. It represents the actual successor of the LS1-f and was developed with a focus on pleasant flight characteristics and improved performance compared to the LS1-f. In the 1980s, the LS4 took top positions in many national and international competitions. With around 1050 units built, the LS4 ranks fourth among the most frequently manufactured gliders. Because of its good glide ratio and good-natured flight characteristics, the LS4 is used today for both high-performance flights and for beginners' training.
The first flight of the LS4 took place in 1980. The improved version LS4-a followed just two years later, which was replaced by the LS4-b around 1990. It was eventually replaced by the LS7 as the manufacturer's most powerful standard class model , but remained in production as a simple and robust glider for club operations . After Rolladen Schneider went bankrupt in 2003, the Slovenian company AMS Flight took over the type support and production of the LS4. The company delivered two copies built in Slovenia in 2007 and had originally planned to continue offering this model. At the end of November 2009, however, the company website announced the decision to discontinue production due to lack of profitability. The model support is now taken over by DG-Flugzeugbau .
If the LS4 variants LS4, LS4-a and -b are counted together, the model is the fourth most frequently built glider in the world. With 1050 units, the LS4 is only surpassed by the SG 38 (approx. 9000 units) by the Grunau Baby (approx. 6000 units) and the LET L-13 "Blanik" (approx. 2700 units).
The LS4 is a single-seat high-performance glider in plastic construction with a 15 m wingspan and a rigid wing profile. It was created using the fuselage and the modification of the wing of the LS3 . The LS4-a version differs from the LS4 mainly in the higher maximum take-off weight , which allows more water ballast to be carried. In addition to a further increased maximum take-off weight, the LS4-b offers further improvements such as automatic rudder connections, an optional tail wheel instead of the previously used grinding spur, an optional additional water tank in the fin and a reinforced hood mechanism that made it possible to fold the instrument panel on the hood to fix. In addition, the b version has a body 18 cm shorter and, in return, a fin that is 11 cm higher. The flight characteristics are not noticeably affected by this.
With the exception of the automatic rudder connections, all the new features of the b version can also be retrofitted in older aircraft, which is why there are now a lot of mixed forms. In particular, many LS4 and LS4-a have been retrofitted with a tail wheel.
For all versions of the LS4, removable winglets are now available for retrofitting, which improve flight performance in slow flight and with water ballast. However, due to the spin behavior changed by the winglets, the water ballast is reduced to 100 kg. The approximately 60 aircraft that have so far been modified in this way are referred to as the LS4 WL . Instead of the clip-on winglets, they can also be flown with the old straight wing tips. In this configuration, the full water ballast can still be carried.
In April 2019 DG Flugzeugbau announced that the Neo-Winglets for the LS4 are now officially approved, without the aforementioned restrictions. Not only did the pilot weight limit of 100 kg previously associated with the winglets no longer apply, the maximum permissible water ballast was also increased to 112 kg and the maximum permissible weight of the non-load-bearing parts to 250 kg. The maximum take-off weight for LS4-a and -b was set at 505 kg (LS4 remains as before 472 kg, LS4a / b previously 525 kg).
LS4 manufactured by AMS corresponded to the b version.
The company M + D Flugzeugbau is currently working on EASA approval for a turbine as a homecoming aid for all versions of the LS4. This jet propelled version is called the LS4-J. A video of the flight of the prototype is available on the Internet.
In the standard class, the world champion of the year 1981 flew an LS4 and in 1982 the first place at the European championship was flown on an LS4. In 1983 the LS4 took the first three places at the German championship and even the first six places at the world championship. Also in 1983 Marlis Bertram won the German Women's Championship and the European Women's Championship with an LS4 and was able to repeat the victory in 1984 at the German Championship. In 1984 a double victory with the LS4 was achieved in the men's championship.
The LS4 can be rated either in the club class or in the standard class , depending on whether it is flown with or without water ballast . In 2018 the glider index was revised and for the LS4 is now 102.5 without winglets and 103.5 with winglets. The LS4 is still very popular with pilots because of its good performance and good-natured flight characteristics.
|class||Standard class (without water ballast also club class)|
|design type||Surfaces: GRP foam sandwich, hull: GRP|
|Wing profile||Wortmann modified|
|length||LS4-a: 6.84 m
LS4-b: 6.66 m
|Wing area||10.5 m²|
|Wing loading||31-45 kg / m²|
|Slightest sinking||0.60 m / s|
|Top speed||280 km / h|
|Minimum speed||68 km / h|
|safe load multiples||+5.3 g to −2.65 g|
|Water ballast||160 l, LS4 WL: 100 l|
|Empty mass||235 kg|
|Max. Payload||LS4-a / -b: 110 kg
LS4 WL: 100 kg
LS4 neo: 110 kg
|min. Payload||70 kg (55 kg with three trim weights)|
|Max. Flight mass||LS4: 472 kg
LS4-a / -b: 525 kg
LS4-a / -b neo: 505 kg
|Max. Mass d. non-structural parts||LS4-a / -b: 230 kg
LS4 neo: 250 kg
|index||102.5 or 103.5 with winglets|
- Flight manual LS4-a / b
- Georg Brütting : The history of the LS aircraft. DG Flugzeugbau GmbH, archived from the original on December 15, 2010 ; accessed on March 16, 2019 .
- Type certification of the LS series - EASA-TCDS-A.095 (PDF; 409 kB)
- LS4 at Sailplanedirectory
- Website of AMS, the current manufacturer
- ↑ Günter Schapke, Werner Scholz, Gerhard Waibel, Wolfgang Binz: obituary Wolf Lemke . In: Air sports . ( dg-flugzeugbau.de ).
- ↑ a b c Description of the LS4 versions on the AMS-Flight website
- ↑ www.dg-flugzeugbau.de ( Memento from October 27, 2010 in the Internet Archive )
- ↑ TM4049 - LS4 neo winglets officially approved. Retrieved May 20, 2019 .
- ↑ TM4049 FE-29-01. DG Flugzeugbau, March 5, 2018, accessed February 12, 2020 .
- ↑ Get the Jet | M + D aircraft construction. Retrieved May 9, 2018 .
- ↑ Jan Warnken: LS4 MDTJ-42 Turbine Lowpasses. In: Youtube. July 27, 2014, accessed June 19, 2019 .
- ^ Brütting , Willberg, Hüls: The most famous gliders in the world. First edition 2009, ISBN 978-3-613-02999-6 , p. 148.