Maryland team readies Gamera II for next human-powered helicopter record
By Paul Ridden
June 15, 2012
Last July, the frantic pumping of upper and lower limbs of intrepid pilot Judy Wexler managed to keep the huge Gamera human-powered helicopter in the air for a record-breaking 11.4 seconds. The student team from the Alfred Gessow Rotorcraft Center at the University of Maryland's Department of Aerospace Engineering has since been busy refining and redesigning the craft for another stab at the elusive US$250,000 American Helicopter Society's Sikorsky Prize. Gamera II has been built for longer flight duration and is lighter and tougher than its predecessor, with improved transmission and enhanced rotor design. The new x-shaped craft is set to take off next week for its first test runs and the team is confident that existing record times will be smashed... but will it nab the ultimate prize?
Gamera II is reported to be a good deal lighter than its predecessor, with the team managing to shave off 35 pounds (15.8 kg) to give it a total weight of just 71 pounds (32.2 kg). The large x-shaped frame has still been constructed using the micro-truss structures developed for the original quad-rotor craft, but have been employed more extensively throughout the frame. At the end of each point of the cross is a new enhanced rotor blade, designed with the help of custom-built optimization software. An increased taper ratio is said to have improved aerodynamics and root stiffness of the blade spar, which results in increased ground effect and keeps tip deflections low.
The engine at the heart of Gamera II is the human pilot, and this year three pilots will man the hand and foot cranks of the redesigned cockpit. The team comprises amateur bike race and assistant research scientist in the University of Maryland Department of Astronomy Dennis Bodewits, alternate pilot for the first Gamera and Ph.D candidate in Clark School's mechanical engineering department Kyle Gluesenkamp, and keen cyclist Colin Gore, who is also a Ph.D candidate but in the School's materials science and engineering department, and was another alternate pilot for the original craft. They're all in the same weight range of 135 - 145 pounds (61.2 - 65.7 kg) and reportedly have (and will need) excellent power to weight ratios.
The team fully expect Gamera II to remain in the air for more than the 60 seconds required to meet the first exacting criteria of the Sikorsky Prize, and has recently been using a test rig to explore the power needed to achieve an altitude of 3 meters (9.84 feet) above the ground at some point during the flight.
The following teaser video has been released ahead of next week's test runs:
More attempts are scheduled to take place in August. We'll be keeping an eye on the progress of Gamera II and will keep you updated.