 During flight testing of the Fw 191, when deployed, the "Multhopp-Klappe" caused severe flutter.In 1944, in collaboration with Tank and his design team, Multhopp was assigned to a research project to meet and exceed the specifications of the "Reichsluftfahrtministerium" (RLM)'s Emergency Fighter Competition for a single-seat jet-powered fighter intended for performance at high-altitude.His design of the diminutive Ta 183 "Huckebein" (German