The Baumgärtl Heliofly III/57 and Baumgärtl Heliofly III/59 were 1940s experimental backpack helicopters designed and built by the Austrian-designer . Following on from his earlier experiments with strap-on autgyros the Heliofly III/57 was powered by two 8 hp (6 kW) Argus As 8 piston engines each driving a single-blade of the contra-rotating rotors.