Posts Tagged ‘Ornithopters’

The Riout 103T Alerion: The Ornithopter that Almost Took Off

January 9, 2023

I was talking on another comments thread about ornithopters with Brian Burden, one of the many great commenters on this blog. Ornithopters are flying machines that work by flapping their wings like a bird or an insect, unlike helicopters or fixed wing aircraft, which use either propeller or jet engines. Some of the very first attempts at powered, heavier than air flight were ornithopters, whose inventors obviously sought inspiration from nature. As human-carrying aircraft, they haven’t been successful. They work as small models, and the early scale models the pioneering aviation inventors and engineers created did actually work, as have more recent model ornithopters and robots modelled on birds and insects. However there were severe problems scaling them up to work with humans. This did not prevent a series of pioneering inventors and aviators trying. One of those was E.P. Frost, who created a series of ornithopters over a decade from the late 19th to the early 20th century. The piccie below shows his 1903 ornithopter, powered by a three horsepower petrol engine and with wings covered in feathers. Another inventor was the French aviator, Passat, who constructed an ornithopter with four flapping wings, covered with fabric rather than feathers, and powered by a 4.5 horsepower motorcycle engine. When it was being tried out in 1912 on Wimbledon Common, it flew for about four hundred feet at a speed of under 15 mph before crashing into a tree. This did not deter Passat, who carried on his experiments into this form of aircraft despite ridicule and the success of fixed wing aircraft.

One of the other aviation pioneers interested in developing this type of aircraft was another Frenchman, Louis Riel, who went on to design the Riout 102T plane, which at one point seemed to be a successful aircraft if further improvements had been made. I found this video about it on Ed Nash’s Military Matters channel on YouTube. This notes the similarity between the four-winged design of the Riout plane and the multi-winged ornithopters of the recent Dune film. This suggests that Frank Herbert, Dune’s author, might have been inspired by Riel’s aircraft. Riel had experimented with a two-winged ornithopter before the First World War before moving on to other projects. He retained his interest in ornithopters, however, and 1937 created the Riout 102T Alerion, which had four, fabric covered planes. Wind tunnel tests were originally promising, until an increase in engine power in one test destroyed the plane’s four wings. Riel had plans to improve and strengthen the wings, but by this time it was 1938. Hitler had annexed Austria and was moving into the Sudetenland, and France needed all its available aircraft to protect itself against German invasion. The project was therefore cancelled.

Brian wondered if computer design and control could result in a practical, human level ornithopter. I think it’s possible, especially as today’s aviation engineers are exploring the instabilities in flight that allow birds to fly so well in creating high performance aircraft, that would need a degree of computer control in flight. One of the issues looks to my like the stresses on the wings caused by flapping, but it may be that this could be solved using the more resilient and durable materials available to modern engineers, which the early pioneers didn’t have. Riel’s plane is not entirely forgotten. Its remains, minus the wings and covering, are in one of the French aviation museums. Perhaps one day they’ll inspire a new generation of engineers to experiment with similar aircraft.