Aircraft

Human-powered Gamera helicopter hovers its way into the record books

Hovering for 11.4 seconds has secured a place in the record books for the Gamera team, and for its pilot Judy Wexler, who made the longest human-powered flight by a female U.S. pilot
Hovering for 11.4 seconds has secured a place in the record books for the Gamera team, and for its pilot Judy Wexler, who made the longest human-powered flight by a female U.S. pilot
View 16 Images
Pilot Judy Wexler gets ready for a sudden burst of hand and foot pedaling
1/16
Pilot Judy Wexler gets ready for a sudden burst of hand and foot pedaling
Diagram of Gamera - each crossbar of the frame is 60 feet long, and has a 42-foot rotor at each of the four points of the cross
2/16
Diagram of Gamera - each crossbar of the frame is 60 feet long, and has a 42-foot rotor at each of the four points of the cross
Getting ready for the record attempt in May 2011
3/16
Getting ready for the record attempt in May 2011
Close up of the lightweight rotor mechanism
4/16
Close up of the lightweight rotor mechanism
Inside Maryland University's Reckord Armory ahead of the record attempt recently
5/16
Inside Maryland University's Reckord Armory ahead of the record attempt recently
Hovering for 11.4 seconds has secured a place in the record books for the Gamera team, and for its pilot Judy Wexler, who made the longest human-powered flight by a female U.S. pilot
6/16
Hovering for 11.4 seconds has secured a place in the record books for the Gamera team, and for its pilot Judy Wexler, who made the longest human-powered flight by a female U.S. pilot
Final checks on the structure of Gamera, which had to undergo emergency repair the night before the record attempt due to crashing during testing
7/16
Final checks on the structure of Gamera, which had to undergo emergency repair the night before the record attempt due to crashing during testing
The lightweight yet strong rotor
8/16
The lightweight yet strong rotor
The lightweight yet strong rotor
9/16
The lightweight yet strong rotor
Gamera's main structure is made from carbon fiber using a specially-developed truss construction method that allows highly optimized composite trusses to be created very quickly
10/16
Gamera's main structure is made from carbon fiber using a specially-developed truss construction method that allows highly optimized composite trusses to be created very quickly
Judy Wexler straps in for the record-breaking flight
11/16
Judy Wexler straps in for the record-breaking flight
The team of graduate and undergraduate students from the Alfred Gessow Rotorcraft Center at the University of Maryland's Department of Aerospace Engineering responsible for designing, building and tweaking a lightweight, four-rotor helicopter that's powered by the human pilot suspended at its center
12/16
The team of graduate and undergraduate students from the Alfred Gessow Rotorcraft Center at the University of Maryland's Department of Aerospace Engineering responsible for designing, building and tweaking a lightweight, four-rotor helicopter that's powered by the human pilot suspended at its center
The four-rotor helicopter is powered by hand and foot pedals
13/16
The four-rotor helicopter is powered by hand and foot pedals
Close up of the very light rotor mechanism
14/16
Close up of the very light rotor mechanism
A National Aeronautic Association official watches the action closely
15/16
A National Aeronautic Association official watches the action closely
1994's Yuri I human-powered helicopter - the current record holder (19.46 seconds at an altitude of 0.2 meters) (Photo: Japan Aeronautic Association)
16/16
1994's Yuri I human-powered helicopter - the current record holder (19.46 seconds at an altitude of 0.2 meters) (Photo: Japan Aeronautic Association)

A biology student has just hovered her way into the record books in a four-rotor, human-powered helicopter named after a giant flying turtle from Japanese kaiju movies. Gamera was built to try and claim the American Helicopter Society's Sikorsky Prize, that was set up in 1980 and has yet to be claimed. The team's first flights in May resulted in a 4.2-second U.S. national record, and now the record page has had to be rewritten again after the young pilot's frantic combination of hand and foot pedaling action kept Gamera in the air for nearly three times longer, during the recent summer flight sessions.

For the last two years, a team of 50 graduate and undergraduate students from the Alfred Gessow Rotorcraft Center at the University of Maryland's Department of Aerospace Engineering has been designing, building and tweaking a lightweight, four-rotor helicopter that's powered by the human pilot suspended at its center. The hope is to build a craft capable of walking away with the American Helicopter Society's Sikorsky Prize of US$250,000.

Diagram of Gamera - each crossbar of the frame is 60 feet long, and has a 42-foot rotor at each of the four points of the cross
Diagram of Gamera - each crossbar of the frame is 60 feet long, and has a 42-foot rotor at each of the four points of the cross

The rules of this challenge - named in honor of helicopter pioneer Igor Sikorsky - state that the craft should get all of its power from the human pilot and that it should thus be capable of hovering for 60 seconds within a 10-meter (32.8-foot) square area. During this time, the lowest part of the machine must reach an altitude of 3 meters (9.84 feet) above the ground - if only momentarily. As of August 2011, no-one has claimed the prize.

The closest so far was 1994's Yuri I (19.46 seconds at an altitude of 0.2 meters/0.65 feet) designed by the Nihon University Aero Student Group. Gamera sports a similar design - with a 42-foot (12.8-meter) rotor at the end of each of the four points of a cross, and the pilot sat in the middle. Each crossbar of the frame is 60 feet (18.2 meters) long.

"The similarities are more a result of convergent evolution than direct inspiration," the team's Joe Schmaus told Gizmag. "Helicopters are notoriously challenging to control and human powered flight has only ever been possible with the aid of ground effect. A quad rotor is the only configuration we have identified that is passively stable and allows the rotors to be as deep in ground effect as possible."

Final checks on the structure of Gamera, which had to undergo emergency repair the night before the record attempt due to crashing during testing
Final checks on the structure of Gamera, which had to undergo emergency repair the night before the record attempt due to crashing during testing

Gamera's main structure is made from carbon fiber using a specially-developed truss construction method, that allows highly optimized composite trusses to be created very quickly. The team also developed a novel method to minimize buckling, where airframe trusses at critical points have been reinforced with so-called baby trusses. Elsewhere, the craft is made of balsa, foam, mylar, and other lightweight materials to help keep its weight down - the entire weight is just 210 pounds (95.25 kg), including the weight of the pilot - while also offering structural strength.

The lightweight pilots used throughout the project have also been experienced cyclists, and were free to design their own training regimes based on their specialist knowledge. The team "became aware through our testing that a more focused training plan that optimized for muscular endurance rather than cardiovascular endurance, and one which trained the motion that is unique to Gamera, would produce even better results," said Schmaus. "Moving forward we are working with specialists in Biomechanics to develop a targeted training plan."

On the eve of the most recent record attempt inside the University's Reckord Armory, Gamera crashed during testing - forcing an emergency all-night repair. However, the next day a few bleary-eyed team members watched as pilot Judy Wexler powered aloft for 12.4 seconds in the presence of officials from the National Aeronautic Association (NAA). However, it's a time of 11.4 seconds from a subsequent flight that's just been confirmed as a new national record by the NAA and submitted to the Fédération Aéronautique International in Switzerland for consideration as a world record. The flights also represent the longest human-powered flight by a female U.S. pilot.

Judy Wexler straps in for the record-breaking flight
Judy Wexler straps in for the record-breaking flight

Even though the team members believe that Gamera is capable of longer duration flights, they are now faced with something of a dilemma.

"The Sikorsky Prize has the very ambitious target of 10 feet and 60 seconds that we do not think our current vehicle can achieve," said Schmaus. "Through the development of Gamera we have learned many things about extreme ground effect aerodynamic design and also about lightweight structural design. At this point we are combining these two knowledge bases to determine whether to go for another record setting, but not prize-winning, flight with Gamera or put all our energy into designing a vehicle capable of the Sikorsky Prize."

The next phase of the Gamera project will be decided shortly. Updates will appear on the project's website.

In the meantime, you can watch all 12.4 exhilarating seconds of human-powered flight in the following video:

Gamera's July 13, 2011 Flight

20 comments
Samantha Renault
So it\'s capable of lifting a lot of weight while being quite light itself. Replace the human being with small gasoline motors and... no... still wouldn\'t work outside and there\'s no way to steer the thing. Beyond being neat I can\'t see any practical applications. Nor can I envision any spinoff technologies that could come from this. But maybe I\'m wrong, feel free to correct me. Sure you could claim this is driving up research on lighter materials but it really isn\'t, there are a million other and bigger things driving up demand for lighter materials. I think this is all about getting some attention for the university. Or maybe it\'s not really for anything.
Slowburn
They need to get a world class sprinter for the pilot. It should not make the craft twice as heavy to make it support two pilots, but that would depend on the rules allowing it.
Slowburn
RE Samantha Renault They are teaching problem solving, and outside the box thinking. And ultra-lightweight structures translate into ultra-strong structures very well.
Vic Vicarious
How clever on one side and \"primitively unforseing \" are they to try this in such a space restraining area.
Paul Anthony
DIdn\'t it say it had to go like 10 feet in the air?
Jess Atwell
Icharyus and DaVinci were right.
Phileaux
For a better power to weight ratio they should use a man. I agree with Slowburn they need a sprinter. Using a cyclist is half right, most have pathetic upper body strength. Yes, you need some endurance but only for 60sec. A wrestler would be better, can get very lean and better upper body strength.
Ryan Mertens
Watts per/kilois what they need...and a woman is far inferior @ that. I was a former track cyclist with over a 20watt/kilo power output. To cover your 60 seconds you need a kilo specialist. A kilo specialist can generate over 1000watts for a 60 sec duration. I wonder if they had an ergometer on the bike.
BigGoofyGuy
I think it is way cool I think it is a great attempt. Perhaps they add control in a future version. :)
Hilary Albutt
That design will never achieve controllable lift even with a electric motor attached. The rotor designs are some of the worst I have ever seen, The lag and energy required to overcome the drag, forget it.