After leaving the propeller laboratory at Fischamend, Balaban became chief engineer at UFAG. Working with Oberingenieur Stanko Bloudek, Balaban proposed a free-flying helicopter to Flars. In return, Balaban received detailed specifications that he felt were unrealistic and well beyond what could be reasonably achieved. On 27 August 1917, Balaban and Bloudek proposed to Flars a helicopter design that appears simple and practical. If accepted, UFAG agreed to have the airframe ready for testing within four weeks after delivery of a 100hp rotary engine. But Flars declined to support the work, much to Balaban's regret. Flight experimentation, performed at UFAG with a model having a 1.5m rotor diameter, demonstrated, perhaps for the first time, that auto-rotation in event of engine failure was feasible.
Peter Grosz "Austro-Hungarian Army Aircraft of World War I", 2002