__NOTOC__ The Kress ''Drachenflieger'' (German: "Dragon-flier") was an experimental aircraft constructed in

Austria-Hungary Austria-Hungary, often referred to as the Austro-Hungarian Empire,, the Dual Monarchy, or Austria, was a constitutional monarchy and great power in Central Europe between 1867 and 1918. It was formed with the Austro-Hungarian Compromise of ...

in 1901. While taxiing trials proved successful, the aircraft lacked sufficient power to fly, and was wrecked in the course of testing on 3 October. It was built by

Wilhelm Kress Wilhelm Kress (29 July 1836 in Saint Petersburg – 24 February 1913 in Vienna) Born of German (Bavarian) parents in St. Petersburg in 1836. Moved to Vienna in 1873, where his self-propelled flying models attracted much attention. He became a na ...

with the assistance of a 5,000- krone grant from Emperor Franz JosefGregorat 2007 in an attempt to create the first

heavier-than-air An aircraft is a vehicle that is able to flight, fly by gaining support from the Atmosphere of Earth, air. It counters the force of gravity by using either Buoyancy, static lift or by using the Lift (force), dynamic lift of an airfoil, or in ...

flying machine. The aircraft was constructed as a large, open-truss structure of steel tubing with three sets of wire-braced monoplane wings placed in tandem along its length. The sets of wings were placed at uneven heights with respect to the major axis of the aircraft to prevent aerodynamic interference between them.''Scientific American'' 137 The undercarriage consisted of two aluminium pontoons with hardened keels, intended to allow the Drachenflieger to take off from and land on water or ice. Three rudders were linked to a common control stick and were to provide steering on water and in the air. Power was provided by a Daimler petrol engine driving two large

screw A screw and a bolt (see '' Differentiation between bolt and screw'' below) are similar types of fastener typically made of metal and characterized by a helical ridge, called a ''male thread'' (external thread). Screws and bolts are used to f ...

-type two-bladed propellers, the first attempt to use an internal combustion engine to power a heavier-than-air aircraft.Nicolaou 1998, 10 The fabric-covered propellers were mounted pusher-fashion on pylons above and on either side of the main truss, between the second and third sets of wings, and were designed to counter-rotate. The engine would prove to be the aircraft's downfall. Kress had originally intended to have an engine specially built, calculating that he needed 37 kW from an engine weighing not more than 220 kg (475 lb).Gunston 1992. 31 When the cost of this proved prohibitive, he purchased an automobile engine already in production which had an output of just 22 kW (30 hp) but weighing nearly twice as much as Kress' calculations allowed for. Initial trials on water as early as March 1901 confirmed that the poorer power-to-weight ratio would be a problem. Nevertheless, other elements of the design proved sound, and the Drachenflieger was successfully controlled while taxiing, even against a headwind. Unable to afford to replace the engine, Kress continued taxiing trials. The last of these was on 3 OctoberGunston gives 15 October on the Wienerwaldsee reservoir at

Tullnerbach Tullnerbach is a municipality in the district of St. Pölten-Land in the Austrian state of Lower Austria. It was here in 1901 that Wilhelm Kress failed at his attempt of motorized seaplane flight on the Wienerwaldsee. The town belonged to Wien-Umg ...

, in which he was forced to swerve suddenly to avoid a groyne. As a result of the violent maneuver, the supports for one of the pontoons failed, causing the Drachenflieger to capsize and sink.

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* * * * * {{cite book , last= Taylor , first= Michael J. H. , title=Jane's Encyclopedia of Aviation , year=1989 , publisher=Studio Editions , location=London 1900s Austro-Hungarian experimental aircraft Floatplanes Tandem-wing aircraft Single-engined pusher aircraft