Rudiger Kunz

Rüdiger Kunz (1926–2013) with record driver Wilhelm Lischak (left in the picture) visiting the “Vintage Glider Rally”, Spitzerberg, 2011

Rüdiger Kunz (born November 17, 1926 in Stockerau ; † July 28, 2013 in Bad Vöslau ) was an Austrian aeronautical engineer, aircraft designer, and glider pilot.

youth

Rüdiger Kunz was born to Sudeten German parents. The father was a designer in the gun department of the Škoda company in Pilsen. Kunz completed elementary school and high school in Baden. He then attended the engineering school in Mödling (forerunner of today's HTL ), aircraft construction department. At the age of 16, Kunz was in possession of the three gliding licenses (A, B and C certificates) that were issued at the time. Kunz enrolled at the Vienna University of Technology, but had to break off his studies with the death of his father in 1949.

Aeroclub

In 1950, Kunz began a long career in aircraft development, initially as technical director in the newly founded aeroclub. Kunz was the contact person for all technical problems and made a name for himself as a technical expert in aircraft accident investigations. He was also a glider instructor and trained a. a. the Austrian record pilot Wilhelm Lischak.

Kunz was heavily involved in the license construction - the Aeroclub had a license agreement with Scheibe-Flugzeugbau - of a two-seater standard glider training aircraft and, for reasons of flight safety, campaigned intensively for tubular steel fuselages instead of wooden construction. At this point in time, as a flight accident expert, Kunz was very familiar with the wooden construction, especially the severity of injuries that were caused by the construction in apparently minor accidents.

Standard Austria

Rüdiger Kunz is the designer of the Standard Austria S performance glider . Competitive gliders at that time were designed for the best gliding at 80 to 90 km / h and were optimized for a lift coefficient of c _A = 0.8. Open class aircraft achieved an aerodynamic quality of 27 to 30 in this speed range, but only 22 at 140 km / h. Kunz optimized Standard Austria for a lift coefficient of c _A = 0.2 with a best glide at 140 km / h. The idea was that the then new FAI regulations for the finish-return and triangle competitions required high speeds. At the gliding world championship in Cologne-Butzweilerhof in June 1960, Johann Fritz flies behind the Polish team with a gap of approx. 4 km - on his return to the field he stabs and flies over the finish line just 20 seconds behind the Polish team in a drawn-up corner. With this he achieved victory in the daily classification with an airplane of the standard class and beats the open class.

Rüdiger Kunz and the Austrian Aero Club received the OSTIV award for the best glider in the standard class for their Standard Austria . Thanks to the good performance of the 2nd and 3rd machines at the World Championships in Cologne, many orders were received from all over the world. A series production did not come about in Austria.

SGP 222

Kunz designed the SGP 222 : After the accident of the twin-engine M-222 designed by Meindl on August 2, 1959, Kunz was appointed by the Minister of Transport as technical director of the accident investigation. At this point in time he had been working part-time on the Aircraft Accident Commission for 12 years and had a good reputation as a technical expert.

The accident report was ready after four weeks. Kunz recognized numerous shortcomings, for example:

• The unladen weight of the aircraft was far too high. It just corresponded to the maximum take-off weight.
• The forward shift of the neutral point due to the influence of the hull and the wide engine pods was not properly taken into account. The neutral point was actually 12% further ahead than assumed. As a result, the aircraft was operated with a center of gravity that was too far back and was therefore indifferent about the transverse axis.

After a conversation with the general director of SGP, Kunz was commissioned with the new design. Since Kunz was busy with the series introduction of Standard Austria at this time, he was only able to take up the position 11 months later. The new design was named SGP 222.

• Kunz installed a motor with a higher output (Lycoming, 200 HP instead of the previous 160 HP) in order to increase the single-motor output.
• He changed the profile especially between the fuselage and the wing nacelle.
• The angle of incidence in the inner area of ​​the wing (between fuselage and engine nacelle) was reduced by 2 degrees compared to the outer area in order to take into account the updraft from the engine nacelles and to avoid detachment between the engine nacelle and the side wall of the fuselage.
• Kunz reduced problems with noise in the cabin by slightly V-positioning the enlarged horizontal stabilizer.
• The vertical stabilizer was also enlarged.
• In addition to the trim wheel and trim tab, Kunz also uses an innovative trim that is automatically operated with the flap lever. Flaps could thus be operated without changing the load.

The glide ratio of the SGP-222 was a remarkably high value for a twin-engine aircraft, namely 1:14. The aircraft now had excellent flight performance and flight characteristics even in single-engine flight and was approved according to FAR Part 23 in the USA.

Bölkow visited SGP in Wiener Neustadt and showed interest in the SGP 222 after a demonstration flight. He signed a contract for 100 units. For political reasons, however, this was never countersigned and the aircraft did not go into series production and was scrapped.

Special projects

After the failure of series production of the SGP 222, Kunz optimized z. B. Fan blades in cooling towers at a power plant in Iran. These blades were previously made of aluminum and overloaded the electric motor when starting up. The wings showed cracks after a short time. Kunz constructed new wings made of GRP .

Bölkow Junior

The contact with Bölkow gave Kunz the opportunity to fly the Bölkow 208 Junior . He found some shortcomings: (1) the seat back, which was too steep, which was too steep because the spar bridge was not intended. The spar was redesigned at Kunz's suggestion after a conversation with Bölkow. This was already the designer's wish, but it was not able to assert itself at Bölkow. (2) The wing-fuselage transition (high-wing aircraft) was poorly resolved because it led to a detached flow. Kunz made a stall attempt at full throttle, and shortly before the stall, suddenly switched the throttle to idle. The plane then went into a tailspin.

airbus

On January 1, 1970, Kunz started at Airbus in Ottobrunn as a technical coordinator in the program management of the southern German Airbus component and was appointed program manager for the southern German Airbus component as early as 1972.

Kunz and the carbon fiber construction: Kunz initiated CFRP as a material in civil aircraft construction. The floor slabs were part of the load-bearing structure for the first time. At that time, CFRP was ten times more expensive than conventional GRP honeycomb. However, Kunz convinced the head of the ATLAS group of the advantages: low weight and long service life. The ATLAS group then requested floor panels made of CFRP for the Airbus. The more expensive material paid for itself after just one year thanks to its lower weight and the associated higher payload.

Eurofighter

In April 1977 Kunz switched to the Eurofighter project (at that time Jäger 90) as head of technical development (Manager Configuration Development) at the Military Aircraft Division. Kunz was significantly involved in the configuration ( delta wing with canard in front of the cockpit) of the Eurofighter EF 2000 . He recognized the advantages of a canard that is controlled in such a way that the configuration is indifferent in the subsonic and indifferent to slightly stable in the supersonic. The canard has the further advantage that returning aerodynamic moments can be generated even at high angles of attack and there are no trim resistances, especially in supersonic conditions.

Singer

Towards the end of his active career, the Austrian Rüdiger Kunz worked at Daimler Benz Aerospace (formerly MBB) on the hypersonic project “ Singer ” as “Head of Configuration Design”. The two-stage hypersonic transport concept "Singer" was intended as a cost-effective transport system for geostationary satellites of up to 5 tons and was developed under the direction of the DGLR and the German aircraft industry with the participation of research institutes.

After retiring at the age of 65, Kunz worked for the company for two more years as a consultant.

World records

• Kunz designed the wing with which Felix Baumgartner succeeded in gliding across the English Channel in 2003.
• Kunz worked as technical advisor to Felix Baumgartner in the Red Bull Stratos project.
• Kunz worked as a consultant for the Austrian record pilot Wilhelm Lischak, who set eight FAI records with the LW-02. The single-seat LW-02 is an in-house construction in wood.
• Kunz supported aircraft self-builders until recently, for example in the context of lectures at the Austrian Igo-Etrich-Club

Web links

• Cross-country pilots' day 2004 (PDF; 284 kB)
• Standard Austria