Julius Hatry
He is remembered for his contributions to sailplane development in the early twentieth century and for building the world's first purpose-built rocket plane, the Opel RAK.1.
References from Alexander Lippisch and Oskar Ursinus helped him gain his first design contract, for a motor glider which never actually flew due to problems with its powerplant.
As early as 1922, Julius Hatry, nicknamed "Uss", became a member of the Mannheim Aviation Club and through this came into contact with the first Rhön competitions.
He began studying engineering at the Technical University of Munich and worked as a flight instructor in Rossitten (East Prussia), where he also designed large aircraft models for the first time.
He had met Alexander Lippisch and Oskar Ursinus in the aviation scene and was therefore commissioned to design a cell for a motor glider.
As a scientific publication, it remained known only to a narrow circle of specialists and it was not until 1983 that Hatry published his equations, when they were already the subject of historical research.
Von Opel piloted himself the spectacular speed record drive of the RAK2 at the AVUS racetrack in Berlin, before a huge crowd and world media in 1928.
In order to maintain secrecy, the tests were started with the aircraft, which was equipped with Sander's rockets, in a meadow near the “Mönchbruch” hunting estate near Frankfurt.
After a first successful test flight by von Opel in early September at "Jagdgut Mönchbruch" using a winch-launch procedure, on September 17, 1929, the prototype and the final launch catapult was ready and Hatry was able to travel about 500 meters at a height of 20 meters at a speed of 100 km / h, propelled by three solid fuel rockets that had 350 kilopond thrust and four seconds of burn time.
Fritz' sister Elinor von Opel had to flee Germany in a dramatic manner, hunted by SS troops, together with her two sons, the younger one was Gunter Sachs von Opel, to Switzerland in 1935, due to a bitter divorce battle and a public aversion to the Nazi leadership friends of her ex-husband.
Friedrich Sander was engaged in German military projects under General Walter Dornberger but was imprisoned for treason by the Nazis and forced to sell his business.
A bitter rivalry erupted between them on who had the greater share in the plane construction: the technology designer or the financier and program head.
Nevertheless, Hatry suffered lifelong trauma due to injustice, unfulfilled hopes and a very long concealment of his actual achievements.
Hatry returned devoting himself to studying the various problems of aerodynamics, gas dynamics, thermodynamics, ballistics and others that arise when designing rocket-powered aircraft.
Dornberger showed a lot of interest and ordered a comprehensive elaboration from Hatry on all conceivable possible uses of missiles, including as a weapon.
Hatry himself wrote later at great age, not without bitterness: "In this way, on the one hand, I was spared the typical research fate that a purposeless search for expansion of human knowledge and possibilities is steered through time events in a direction that was never inherent in the original intentions.
As a screenwriter and assistant director, he made entertainment films for the Tobis company in Berlin, in which Theo Lingen, Leni Marenbach and Rudolf Prack contributed, among others.
Despite all the horror of the events he portrayed, Hatry closed his description denouncing Hitler and Nazi Germany as root cause of the disaster.
He dubbed French films and even represented Germany with his own movie "Reitanleitung für eine Geliebte" at the 1950 Venice Biennale.
[3] Nationwide, Hatry procured suitable retail locations for large chain stores such as "Quelle", "Tengelmann", and others all over Germany.
In 1985, he took over the position of coordinator for the short biographies of the Pioneers series and a year later he was involved in the re-establishment of the district group North Baden-Palatinate, which he headed until his death.
The DGLR awarded Hatry the status of a "Corresponding Member" (Honorary Fellow) at the German Aerospace Congress 1992 "in recognition of his pioneering designs and experiments for rocket propulsion for aircraft".
The city of Mannheim named a street in the Glückstein Quarter after him and on November 22, 2016, decided on the honorary status for his grave in the main cemetery.
