Two of the three teams active in the American Helicopter Society International's $250,000 Igor I. Sikorsky Human-Powered Helicopter Competition could stage prize attempts any moment now.
Established in 1980, the AHS Sikorsky Prize is one of the longest-running competitions in aviation. To win, the helicopter must hover for 60 sec, achieve an altitude of 3 meters and stay within a 10 x 10-meter box.
The AeroVelo team, backed by the University of Toronto, is testing the Atlas, a quadcopter with four 33.5-ft-diameter two-blade rotors, that weighs in around 120 lb. Check their Twitter feed for progress updates.
Piloted by team co-lead Todd Reichert, the Atlas is the only one of the three contenders with manual flight controls. Here is video of the helicopter's first flight on August 28 last year:
The University of Maryland is testing the Gamera II, a refined version of a human-powered helicopter that has already set duration records. Check their Twitter feed for progress updates (getting close!).
The Gamera II has four 45-ft-diameter two-blade rotors, and weighs just 78 lb. The pilot uses both hands and feet to power the aircraft, and as a result requires an electronic control system. Here is video of the Gamera II making a 65-sec flight in June 2012:
The third contender is the Upturn II, under development by the California Polytechnic Institute at San Louis Obispo. The aircraft has two blades of 85ft diameter, and two of 48ft diameter with 6ft propellers at the tips to drive the rotor.
It started out weighing 95lb, but lighter, more-stable version of the Upturn II is in the final stages of manufacture and is expected to fly within a month or so - by which time the prize could be won, of course. Here is video of the original Upturn II flying at CalPoly on November 10 last year: