Schleicher Ka 4

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Schleicher Ka 4
Schleicher Ka 4 Rhönlerche
Type: Wooden glider with tubular steel fuselage
Design country:

Germany Federal RepublicFederal Republic of Germany BR Germany

Manufacturer:

Alexander Schleicher GmbH & Co

First flight:

7th December 1953

Production time:

1953-1963

Number of pieces:

338

The Schleicher Ka 4 Rhönlerche II - named after the Rhön - is a two-seat glider that was designed in 1952 by the aircraft manufacturer Alexander Schleicher .

history

Between 1953 and 1963 the Ka 4 Rhönlerche II was produced 338 times. It has a span of 13 m and a glide ratio of 19. This very low glide ratio earned it the nickname “Rhönstein”. Nevertheless, she has a very good-natured flight behavior and was a popular training aircraft. Christian Knabe flew a considerable distance of 275 kilometers with her in 2003, which corresponds to a flight of 550 kilometers in the standard class Discus aircraft . The Rhönlerche is listed in the glider index with 54 points and thus has the weakest index of all two-seater gliders in the list.

construction

Shell of the "Rhönlerche" of Akaflieg Frankfurt at Goethe University in 1957
Shell of the "Rhönlerche" of Akaflieg Frankfurt at Goethe University in 1957
Hull of a Ka 4 in an unstrung state
Schleicher Ka 4 Rhönlerche

The Rhönlerche is a stripped shoulder-decker in mixed construction. The horizontal stabilizer is designed as a damped normal stabilizer . The fuselage is a covered tubular steel framework that is planked on the aircraft nose and on the vertical stabilizer, while the wings, the horizontal stabilizer and the rudders are made of wood. The tubular steel construction makes the fuselage very stable so that it can withstand harder landings . The Rhönlerche is only sprung by a runner mounted on rubber blocks. In addition to the runner, the Rhönlerche II has an unbraked main wheel and a grinding spur. The underside of the aircraft is covered with durable synthetic leather.

After a tendency to rudder flutter was determined, the ailerons were given counterweights to shift the rudder's center of gravity forward. The rudder is equipped with an aerodynamic rudder compensation, as part of the rudder is in front of the axis of rotation. This part is located above the tail unit.

The hood of the Rhönlerche II is made of several parts that are screwed to the hood frame. To ensure a good view from the rear seat, a skylight is installed between the wings.

Instead of backrests, the Rhönlerche has bulges in which either a parachute or a back cushion can be placed. The format of these bulges corresponds to the parachute used in the past; However, the parachutes in use today no longer fit in.

Flight characteristics

Schleicher Ka 4

The very low glide ratio makes flying the Rhön Lark a special challenge. Since it can fly very slowly, it rises very well in thermals and longer flights are possible with it. The narrow wingspan of only 13 meters makes it a very manoeuvrable aircraft. As with many oldtimers, the airbrakes of the Rhönlerche are very poorly effective and the side glide must be used to reduce altitude during higher approaches. In addition, the design of the ratchet lever as a lever, which is attached near the airbrake lever, often confused these levers and flew in without pulled airbrakes, because they operated the tow release instead . Since the main wheel is not braked, only the runner can be used to brake on a short runway.

Motor lark

A motor lark

As motor lark various motorized conversions of Rhönlerche be called. Usually the front pilot's seat was removed and replaced with an engine. For example, VW 1600 engines were used, and the tandem landing gear , which is common in pure gliders , was replaced by a tail wheel landing gear. These versions are usually registered as motor gliders in Germany . An exception is, for example, the Schwämmle HS.3 Motor Lark , which is approved in the E-Class .

There was also a two-seater version with two small motors attached to boom gondolas. This version has been described by the trade press as flying well, but "astonishingly noisy" (surprisingly noisy).

Technical specifications

Schleicher Ka 4 Rhönlerche at the start
Landing with a Rhönlerche in a corn field near Rheinberg
Parameter Data
Years of construction 1952-1963
constructor Rudolf Kaiser , L. Coronation
Wingspan 13 m
length 7.3 m
height 1.5 m
Wing area 16.34 m²
Wing extension 10.34
Empty mass 220 kg
Wing profile inside and middle: Gö 533 / outside: Gö 532
Max. Takeoff mass 400 kg
Top speed 170 km / h
Slightest sinking 0.95 m / s
Glide ratio 19th

Received aircraft

  • D-8533 Rhönlerche II in Hockenheim (private)
  • D-8531 Rhönlerche II from the Flugsportclub Pforzheim and Straubenhardt
  • D-6267 Rhönlerche II from the Dinslaken air sports club
  • D-7144 Rhönlerche II from the Flugsportclub Hannover
  • D-5499 Rhönlerche II, Leo Junior Hermeskeil flight exhibition in Germany
  • D-8594 Rhönlerche II, Technik-Museum Speyer
  • D-7125 Rhönlerche II, German Gliding Museum on the Wasserkuppe
  • Rhönlerche II in the Museum of Flight - East Fortune, North Berwick, GB
  • D-3584 Rhönlerche II V2, Frank Neupert, Schweinitz
  • OE-0583 Rhönlerche II of the Austrian Aviation Museum
  • OE-0858 Rhönlerche II from the Flugsportzentrum Tirol
  • OE-5512 Rhönlerche II from the Flugsportzentrum Tirol
  • D-4378 Rhönlerche II from the Flugsportzentrum Tirol
  • HB-664 Ka 4 “Vreni” of the Bern glider group
  • HB-1245 Ka 4 of the Sailing Flight History Foundation
  • D-8365 Ka 4 des Sportflug Niederberg e. V. Heiligenhaus

See also

literature

  • Peter F. Seliger: Rhön-Adler. 75 years of Alexander Schleicher glider construction. 2nd edition, Verlag RG Fischer, Frankfurt a. M. 2003.
  • Richard and Monique Ferrière: Les Planeurs et Motoplaneurs d 'Alexander Schleicher 1951–1981. Motorbuch-Verlag, Stuttgart 1988, ISBN 3-613-01190-5 .

Web links

Commons : Schleicher Ka 4  - Collection of images, videos and audio files

Individual evidence

  1. ↑ Alexander Schleicher: All types of aircraft since 1951 , accessed on December 18, 2018.
  2. ↑ a b Ka 4 Rhönlerche II - Technical data. Alexander Schleicher, archived from the original on June 14, 2014 ; accessed on November 11, 2018 .
  3. ↑ LSV Unna-Schwerte: 275 km with the Rhönlerche  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. , accessed on Jan 17, 2010@1@ 2Template: Toter Link / lsv-unna-schwerte.de  
  4. ↑ SUOMESSA REKISTERÖIDYT ILMA-ALUKSET (PDF)  ( Page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. : Summary of the Finnish aircraft register dated January 1, 2010 (page 133 in PDF file), accessed on March 28, 2010@1@ 2Template: Dead Link / www.civilaviationauthority.fi  
  5. ↑ Portrait of the Schwämmle HS.3 Motorlerche D-EGLK at airport-data.com , accessed on March 27, 2020
  6. ^ Peter Ross: World motor-glider meeting. In: FLIGHT International, June 21, 1973, pp. 950–951 ( available online )
  7. ^ Flyers from club members. In: Flugwerk-mannheim.de. Retrieved March 27, 2020 .
  8. ^ Website Flugsportclub Pforzheim and Straubenhardt eV
  9. ↑ Homepage Luftsportverein Dinslaken eV , accessed on March 4, 2010
  10. ↑ Homepage Flugsportclub Hannover , accessed on February 9, 2010
  11. ↑ a b The Virtual Aviation Museum: Schleicher KA 4 Rhönlerche ( Memento from August 21, 2008 in the Internet Archive ), accessed on March 3, 2010
  12. ↑ Schleicher "Rhönlerche II". ( Memento from March 6, 2016 in the Internet Archive ) on the website of the Wasserkuppe glider museum
  13. ^ Our Aircraft. (PDF; 360 kB) (No longer available online.) National Museum of Flight, archived from the original on August 6, 2009 ; accessed on January 13, 2011 (English, p. 26): "Schleicher Ka-4 Rhönlerche II - GA 591 (D-0359) c / n 209"
  14. ↑ List of participants (pdf) Gliders Classic Open Eggersdorf 2005
  15. ^ Ka 4 Rhönlerche II in the Austrian Aviation Museum (AAM) Bad Vöslau
  16. ↑ a b c K4 - "Rhönlerche". ( Memento from April 7, 2011 in the Internet Archive ) on the website of the Flugsportzentrum Tirol
  17. ^ Website Segelfluggruppe Bern
  18. ↑ Res Stotzer: Rhönlerche - Foundation sailing flight history. Retrieved October 1, 2019 .
  19. ↑ Homepage Sportflug Niederberg eV