Early history of the Ornithopter

 

The idea of constructing wings in order to resemble the flight of birds dates to the ancient Greek legend of Daedalus (Greek demigod engineer) and Icarus (Daedalus’s son). One of the first recorded – still dilettante – attempts with gliders were those by the 11th century monk Eilmer of Malmesbury (recorded in the 12th century) and the 9th century poet Abbas Ibn Firnas (recorded in the 17th century); both experiments ended with lasting injuries to their pilots. Roger Bacon, writing in 1260, was among the first to consider a technological means of flight. In 1485 , Leonardo da Vinci began to study the flight of birds. He grasped that humans are too heavy, and not strong enough, to fly using wings simply attached to the arms. Therefore he proposed a device in which the aviator lies down on a plank and works two large, membranous wings using hand levers, foot pedals, and a system of pulleys.

The first ornithopters capable of flight were constructed in France in the 1870s. Gustave Trouvé’s 1870 model flew a distance of 70 meters in a demonstration for the French Academy of Sciences. The wings were flapped by gunpowder charges activating a bourdon tube. Jobert in 1871 used a rubber band to power a small model bird. Alphonse Penaud, Hureau de Villeneuve, Victor Tatin, and others soon followed with their own designs.

Around 1890, Lawrence Hargrave built several ornithopters powered by steam or compressed air. He introduced the use of small flapping wings providing the thrust for a larger fixed wing. This eliminated the need for gear reduction, thereby simplifying the construction. To achieve a more birdlike appearance, this approach is not generally favored today.

In the 1930s, Erich von Holst carried the rubber band powered bird model to a high state of development and great realism. Also in the 1930s, Alexander Lippisch and other researchers in Germany harnessed the piston internal combustion engine.

Human Powered Ornithopters

 

Around 1894, Otto Lilienthal became famous in Germany for his widely publicized, partially successful ornithopter experiments. Even though popularly known in English as the Glider King for his earlier gliding experiments, Lilienthal’s new device was in fact an ornithopter with wings powered only by a man’s arm power, as indicated by his invention’s official name of kleiner Schlagflügelapparat (lit. “small flapping-wing device”).

In 1929, a man-powered ornithopter designed by Alexander Lippisch flew a distance of 250 to 300 meters after tow launch. The flight duration was necessarily short due to the limitations of human muscle power. Since a tow launch was used, some have questioned whether the aircraft was capable of sustained flight, however brief. Lippisch asserted that the aircraft was actually flying, not making an extended glide. Later tow-launched flights include Bedford Maule (1942), Emil Hartmann (1959), and Vladimir Toporov (1993). All faced similar limitations due to the reliance on human muscle power.

In 1942, Adalbert Schmid flew a motorized, manned ornithopter at Munich-Laim. It was driven by small flapping wings mounted at the sides of the fuselage, behind a larger fixed wing. Fitted with a 3 hp Sachs motorcycle engine, it made flights up to 15 minutes in duration. Schmid later constructed a 10 hp ornithopter based on the Grunau-Baby IIa sailplane, which was flown in 1947. The second aircraft had flapping outer wing panels.

In 2005, Yves Rousseau was given the Paul Tissandier Diploma, awarded by the FAI for contributions to the field of aviation. Rousseau attempted his first human-muscle-powered flight with flapping wings in 1995. On 20 April 2006, at his 212th attempt, he succeeded in flying a distance of 64 metres, 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.

A team at the University of Toronto Institute for Aerospace Studies, headed by Professor James DeLaurier, worked for several years on an engine-powered, piloted ornithopter. In July 2006, at the Bombardier Airfield at Downsview Park in Toronto, Professor DeLaurier’s machine, the UTIAS Ornithopter No.1 made a jet-assisted takeoff and 14-second flight. According to DeLaurier,[4] the jet was necessary for sustained flight, but the flapping wings did most of the work.

Snowbird Is The Latest Attempt

 

On August 2, 2010, Todd Reichert, an Engineering PhD candidate at the University of Toronto Institute for Aerospace Studies, piloted ‘Snowbird’, surpassed the record set by Ornithopter No.1. Initially towed by a car until lift was achieved, Snowbird sustained 19.3 seconds of flight, covering a distance of 145 meters. Developed by Reichert, Cameron Robertson, James DeLaurier and assistance from students from the University of Toronto and other institutions, Snowbird will become the record holder for the longest sustained flight by a human-powered ornithopter pending confirmation by the Fédération Aéronautique Internationale. Snowbird has a wingspan of 32 metres. The pilot sits in a small cockpit suspended below the wings and pumps a bar with his feet to operate a system of wires that flap the wings up and down. The pilot steers using a pair of metal bars attached to rudders on the back of the aircraft.