David Schwarz (aviation inventor) : biography
David Schwarz ( 20 December 1852, Keszthely, Kingdom of Hungary – 13 January 1897, Vienna) was a Hungarian-Croatian aviation pioneer of Jewish descent.
Schwarz created the first flyable rigid airship, which was also the first airship with an external hull made entirely of metal. He died before he could see it finally flown. Some sources have claimed that Count Ferdinand Graf von Zeppelin purchased Schwarz’s airship patent from his widow, a claim which has been disputed.
About the time of the trial flight crash, and for decades after, various accounts, sometimes conflicting or misleading, were written of the events. Later, Berg, as well as his son, would write negatively of his experiences with Schwarz.
Some sources state that Count Ferdinand von Zeppelin purchased Schwarz’s patent from his widow in 1898, while others claim that the count used the design, however Dr. Hugo Eckener, a Zeppelin biographer, addressed these claims as inaccurate, stating:
Cvi Rotem (1903–1980) wrote the only known biography titled David Schwarz: Tragödie des Erfinders, Zur Geschichte des Luftschiffes, and Robinson reviewed the 187 page manuscript in the March 1984 issue of Buoyant Flight.Dooley A.183 Cvi Rotem wrote that both Berg and Schwarz wished to keep their work secret.
From 3 December 2000 to 20 April 2001 the Museen der Stadt Lüdenscheid held an exhibition which covered Berg, Schwarz and Zeppelin history from 1892 to 1932, with displays of documents, photographs and airship remnants.Schnitzler 2000
Death and maiden flight
Schwarz did not live to see the maiden flight of his airship. Between 1892 until 1896 he was traveled often, which affected his health. Shortly before his death he received news that his airship was ready to be filled with gas. On the 13 January 1897 he collapsed in the street in Vienna by the restaurant "Zur Linde" and died minutes later in a hallway from heart failure. Historical sources speak of a blutsturz (a term meaning either hemoptysis or hematemesis).
The city of Vienna honoured David Schwarz with an ehrengrab (a memorial grave of honour) and with a grabmal (a kind of tomb) at the Vienna Zentralfriedhof (Central Cemetery).
Carl Berg required confirmation of Schwarz’s death, suspecting he had fled to sell his secrets.Dooley A.191 Nevertheless, Berg resumed the work with Melanie, Schwarz’s widow, and together with the Airship Battalion they completed the airship with the addition of a gas relief valve.
This second airship had these specifications:Dooley A.191, citing Douglas Robinson, p. 4
- gas volume: 4610 cubic metres
- length 38.32 metres
- elliptical cross-sectional area: 132 square metre, 15.4 metre wide, 18.2 metre high,
- engine: Daimler weighing 508 kg
- vertical airscrews: three 2.6 metre diameter, two on hull, one above gondolaWhale writes the central screw was for steering
- horizontal airscrew: one mounted under the gondola
- skin: 0.2 mm aluminium plates riveted to framework.
Sean Dooley analyzed the engineering structure from the drawings and considered it deficient, such that the skin took most of the shear stresses, as could be seen in a photo in flight.Dooley A.192
The second airship was tested with partial success at Tempelhof near Berlin, Germany, on 3 November 1897. Airship Battalion mechanic Ernst Jägels climbed into the gondola and lifted off at 15:00. However the airship broke free of the ground crew, and because it rose quickly Jägels disengaged the vertical axis ‘lift’ propeller. At about 130 meters altitude the drive belt slipped off the left propeller, causing a partial loss of steering, resulting in the ship "…[turning] broadside to the wind, [and with the result that] the forward tether broke free." As the ship rose up to 510 meters the driver belt slipped off the right propeller, with the airship thus losing all propulsion. Jägels then opened the newly fitted gas release valve and landed safely in an open area, but the ship turned over and collapsed, being damaged beyond repair.