American Helicopter Society International (AHS International, Booth No. N6304) is marking its 70th anniversary here at Heli-Expo. With 6,100 members from 44 countries, AHS International is dedicated to finding technical solutions for vertical lift, including solving the challenge of human-powered vertical flight. AHS International is offering a $250,000 prize, funded by Sikorsky Aircraft (founded by one of the organization’s charter members, Igor Sikorsky) to the designer(s) of a helicopter that can hover for at least one minute at least 9.84 feet over a 32.8-foot-sided square.