Ornithopters, aircraft that fly by flapping their wings, are a staple at birdman rallies the world over, inevitably resulting in the pilots of such craft plunging headlong into the drink. Now, more than 500 years after Leonardo da Vinci sketched the first human-powered ornithopter in 1485, a team from the University of Toronto have succeeded where so many before them have failed and made aviation history by achieving a world record for sustained flight in a human-powered aircraft with flapping wings.
The record-breaking flight of the craft, called the “Snowbird”, took place on August 2 at the Great Lakes Gliding Club in Tottenham, Ontario. On it the Snowbird managed to sustain both altitude and airspeed for 19.3 seconds, covering a distance of 145 meters (475.7 feet) at an average speed of 25.6 km/h (15.9 mph). That might not sound overly impressive, but it was enough to set a world record for such a craft that is expected to be confirmed next month.
The Snowbird itself weighs just 94 lbs. (42.6 kg) and has a wingspan of 32 meters (105 feet). Although its wingspan is comparable to that of a Boeing 737, the Snowbird development team says its craft weighs less than all of the pillows on board that aircraft. It was piloted and powered by Todd Reichert, an Engineering PhD candidate at the University of Toronto Institute for Aerospace Studies (UTIAS) who lost 18 lbs. (8 kg) of body weight this past summer to facilitate flying the aircraft.
The Snowbird development team comprised two University of Toronto Engineering graduate students: Reichert, and Cameron Robertson (MASc 2009) as the chief structural engineer; UTIAS Professor Emeritus James D. DeLaurier as faculty advisor; and community volunteers Robert and Carson Dueck. More than 20 students from the University of Toronto and up to 10 exchange students from Poitiers University, France, and Delft Technical University, Netherlands, also participated in the project.
The team undertook the challenge to learn to design and build lightweight efficient structures. The research also promoted "the use of the human body and spirit," says Reichert.
"The use of human power, when walking or cycling, is an efficient, reliable, healthy and sustainable form of transportation. Though the aircraft is not a practical method of transport, it is also meant to act as an inspiration to others to use the strength of their body and the creativity of their mind to follow their dreams,” Reichert added.
In 1929, a man-powered ornithopter designed by Alexander Lippisch apparently flew a distance of 820 to 984 feet (250 to 300 m), but because a tow launch was used some have questioned whether the craft was capable of sustained flight. In April 2006, Yves Rousseau succeeded in flying a human-muscle-powered ornithopter a distance of 210 feet (64 m) on his 212th attempt, which was observed by officials of the Aero Club de France. Unfortunately, on his 213th flight attempt, a gust of wind led to a wing breaking up, causing the pilot to be gravely injured and rendered paraplegic.
Professor DeLaurier also had success with an engine-powered ornithopter which we first looked at back in 2004. In July 2006, Professor DeLaurier's machine, the UTIAS Ornithopter No.1 made a jet-assisted takeoff and 14-second flight. According to DeLaurier, the jet was necessary for sustained flight, but the flapping wings did most of the work.
The Snowbird’s record-breaking flight also involved the craft initially being towed by a car until lift was achieved and was witnessed by the vice-president (Canada) of the Fédération Aéronautique Internationale (FAI), the world-governing body for air sports and aeronautical world records. The official record claim was filed this month, and the FAI is expected to confirm the ornithopter's world record at its meeting in October.