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A human-powered aircraft (HPA) is an aircraft powered by direct human energy and the force of gravity; the thrust provided by the human may be the only source; however, a hang glider that is partially powered by pilot power is a human-powered aircraft where the flight path can be enhanced more than if the hang glider had not been assisted by human power. Likewise, HPA inevitably experience assist from thermals or rising air currents. Pure HPA do not use hybrid flows of energy (solar energy, wound rubber band, fuel cell, etc.) for thrust. In nil wind, a flatland-long-gliding aircraft is a form of HPA where the thrust in the nil wind is provided by the running of the pilot; when the pilot loses touch with the ground, his or her thrust ceases to add energy to the flight system and a glide begins; the pilot may or may not add energy after the pilot stops touching the ground. Humans who tow up a manned kite form one type of human-powered aircraft.
Early attempts at human-powered flight were unsuccessful because of the difficulty of achieving the high power-to-weight ratio. Prototypes often used ornithopter principles which were not only too heavy to meet this requirement but aerodynamically unsatisfactory.
As of 2008, human-powered aircraft have been successfully flown over considerable distances. However, they are primarily constructed as an engineering challenge rather than for any kind of recreational or utilitarian purpose.
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The Royal Aeronautical Society's 'Man Powered Aircraft Group' was formed in 1959 by the members of the Man Powered Group of the College of Aeronautics at Cranfield when they were invited to join the Society. Its title was changed from 'Man' to 'Human' in 1988 because of the many successful flights made by female pilots.
Under the auspices of the Society, in 1959 the industrialist Henry Kremer offered the Kremer Prizes of £50,000 for the first human-powered aeroplane to fly a figure-of-eight course round two markers half-a-mile apart.
An early human-powered aircraft was the Gerhardt Cycleplane, developed by W. Frederick Gerhardt at McCook Field in Dayton, Ohio in 1923. The aircraft had seven wings stacked nearly 15 feet (4.6 m) high. The pilot peddled a bicycle gear that turned the propeller. In early tests the aircraft was towed into the air by an automobile, and released. With Gerhardt as the pilot, the Cycleplane was able to maintain stable, level flight for short durations.[1] Its only human-powered takeoff was a short hop of 20 feet (6.1 m) with the craft rising 2 feet (0.61 m).[2]
In 1934 Engelbert Zaschka from Germany completed a large human-powered aircraft, the Zaschka Human-Power Aircraft. On 11 July 1934 the Zaschka-HPA flew about 20 meters on the Berlin Tempelhof Airport; the HPA took off without assisted takeoff.[3][4]
A craft called HV-1 Mufli (Muskelkraft-Flugzeug) built by Helmut Hässler and Franz Villinger (de) first flew on 30 August 1935: a distance of 235 metres at Halle an der Saale. 120 flights were made, the longest being 712 metres in 1937. However it was launched using a tensioned cable and so was not strictly human-powered. [5]
A team of Enea Bossi (designer), Vittorio Bonomi (builder), and Emilio Casco (pilot) met a challenge by the Italian Government for a flight of one kilometre using their Pedaliante in March 1937. The aircraft apparently flew short distances fully under human power, but the distances were not significant enough to win the competition's prize. Furthermore there has been much dispute as to whether it ever took off under the pedal-power of the pilot alone, in particular because there is no record of official observation of it having done so.[6] Some of the arguments for and against the validity of Bossi's claim to have done so are presented by Sherwin (1976).[7] At the time the fully human-powered flights were deemed to be a result of the pilot's significant strength and endurance; and ultimately not attainable by a typical human. As with the HV-1 Mufli, additional attempts were therefore made using a catapult system. By being catapulted to a height of 9 metres (30 ft), the aircraft met the distance requirement of 1-kilometre (0.62 mi) but was declined the prize due to the launch method.[8][9][10]
The first officially authenticated take-off and landing of a man powered aircraft (one capable of powered take-offs, unlike a glider) was made on 9 November 1961 by Derek Piggott in Southampton University's Man Powered Aircraft (SUMPAC) at Lasham Airfield.[11] The best flight out of 40 tried was 650 metres.[12] The SUMPAC was substantially rebuilt by Imperial College with a new transmission system but was damaged beyond repair in November 1965.
The Hatfield Puffin first flew in 16 November 1961, one week after SUMPAC. The Hatfield Man Powered Aircraft Club was formed of employees of de Havilland Aircraft Company and had access to company support. Eventually its best distance was 908 metres. John Wimpenny landed in a state of physical exhaustion. His record stood for 10 years.
Puffin 2 was a new fuselage and wing around the transmission recovered from the original Puffin. It flew on 27 August 1965 and made several flights over a half-mile, including a climb to 5.2 metres. In 1967 Kremer increased his prize money tenfold to £500,000, for no-one had even attempted his challenging course. He also opened the competition to all nationalities as it had previously been restricted to British entries only. After Puffin 2 was damaged it was handed over to Liverpool University who used it to build the Liverpuffin
After this date several less successful aircraft flew, until 1972 when the Jupiter flew 1,070 metres and 1,239 metres in June 1972. In early 1977, a Japanese aircraft - Stork - completed three-quarters of the course before grounding a wingtip. On 23 August 1977 the Gossamer Condor 2 flew the first figure-eight, a distance of 2,172 metres winning the first Kremer prize. It was built by Dr Paul B. MacCready. and piloted by amateur cyclist and hang-glider pilot Bryan Allen. Although slow, cruising at only 11 mph, it achieved that speed with only 0.35 hp.[13]
The second Kremer prize of £100,000 was won on June 12, 1979, again by Paul MacCready, when Bryan Allen flew MacCready's Gossamer Albatross from England to France: a straight distance of 35.82 km (22 miles 453 yards) in 2 hours, 49 minutes.
A Kremer prize of £20,000 for speed went on 1 May 1984 to a design team of the Massachusetts Institute of Technology for flying their MIT Monarch B craft on a triangular 1.5 km course in under three minutes (for an average speed of 32 km/h): pilot Frank Scarabino. Further prizes of £5,000 are awarded to each subsequent entrant improving the speed by at least five percent.
The first human-powered passenger flight occurred on 1 October 1984 when Holger Rochelt carried his sister Katrin in Musculair 1.
The current distance record recognised by the FAI was achieved on 23 April 1988 from Iraklion on Crete to Santorini in an MIT Daedalus 88 piloted by Kanellos Kanellopoulos: a straight distance of 115.11 km (71.53 mi).
In 2010, the DUT Icarus 001 was another concept human powered aircraft. However, due to financial reasons, the project was halted.
Another human-powered aircraft was Todd Reichert's Snowbird. [14][15]
On 10 December 1989 the first human-powered helicopter, the California Polytechnic State University Da Vinci III, flew for 7.1 seconds and reached a height of 20 cm.
The current world record for human powered helicopter is held by a craft named Yuri I, built by a team from the Nihon Aero Student Group (NASG). In 1994, it achieved a height of 20 cm for 19.46 seconds unassisted and unofficially reached 70 cm during a flight lasting 24 seconds.
Machines have been built and flown in the United States, Japan, Germany, Greece, Australia, New Zealand, South Africa, Austria, Canada, Singapore and the United Kingdom, with their total number approaching a hundred.
With further funds from the late Henry Kremer, the Royal Aeronautical Society has announced four new prizes:[16]
The eventual aim is to achieve Olympic recognition as a sport.
There are at least four current attempts underway to claim the £100,000 Kremer Sport prize. One team from Virginia Polytechnic Institute has been active for a number of years designing an aircraft as part of their AE4065/6 class; recent attempts to assemble a wing structure had resulted in critical failure. A second team from the Pennsylvania State University is designing and constructing the PSU Zephyrus as part of their AERSP 404H class. A third team from the Aeronautics Department at Imperial College London is undertaking the premise of Human Powered Flight for one of their 3rd Year Group Design Projects, to investigate its feasibility in the sporting world. Finally, the fourth team consists of 10 MEng students from the University of Southampton and who are designing and constructing the SUHPA (pronounced "soo-pah").[17]
Inventors have built human-powered airships. By gaining lift through buoyancy instead of air flowing past an airfoil, much less effort is required to power the aircraft.[18][19][20]
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