Cyclogiro-rotors:
"D-Dalus can fly vertically as well as a helicopter and has a significantly better forward flight performance. Yet the D-Dalus is far quieter and more economical than a helicopter. A further security plus is the fact that the D-Dalus has no freestanding rotors like a helicopter."
http://www.formquadrat.com/en/transp...us-manned.html
"D-Dalus can fly vertically as well as a helicopter and has a significantly better forward flight performance. Yet the D-Dalus is far quieter and more economical than a helicopter. A further security plus is the fact that the D-Dalus has no freestanding rotors like a helicopter."
http://www.formquadrat.com/en/transp...us-manned.html