'The bird is a machine that operates according to mathematical principles' -Da Vinci
While searching through old emails yesterday for one related to a gift I recently gave to my niece, I stumbled across two that had come in about a year ago and had somehow escaped my attention. One was from John Bailey in the UK and the other from a new contact in South Africa. John Gibbs is a technical writer in the Durban area and, as he describes himself, ‘a backstreet aeronautical engineer’. He had found the Great Blue Machine and was motivated to write a detailed description of his informed views on the future of human powered aviation. I’m going to write him back and request permission to post his letter in the correspondence section, because I hope it will prompt some discussion from John Bailey and Tom Phillips and perhaps others as well. While I was glad to see that we agree on essentially every aspect of innovative aircraft design, John feels that ornithopter R & D is going to waste lots of time, and I feel that it is the area in most dire need of exploration. True, some supplemental power is needed to gain altitude under many conditions but then with a decent glide ratio (which all birds possess), the need for power would be diminished except possibly at landing when a significant amount of flapping would be required for breaking. A bit called “Why don’t airplanes have flapping wings” by Robert Lamb on the Blow Your Mind blog cites the work of Jim Usherwood at the Structure and Motion Laboratory, Royal Veterinary College, University of London. Robert Lamb takes a similar view to John Gibbs when he states that birds are just not very efficient. As a Biology teacher who has spent more than twenty years studying and watching birds, I must disagree. Nature cannot afford to be wasteful and our best way forward as a species is to emulate this principle first. We must ultimately come to understand that the entire infrastructure needed to support the automobile, – including all roads, bridges filling stations, tunnels and manufacturing plants is killing this planet and its riotous biodiversity. With a clear focus on intentional, biologically inspired design, we can learn to travel in the water as the sharks and whales do and take to the sky as the birds, bats and insects do. John and I agree that birds have power to spare and that humans cannot generate an equivalent amount for our size. We can generate some though, and super-capacitors can be used to make up the difference. Birds, Bats, and Bugs are WAY more versatile and maneuverable than anything we have some up with so far. They bulk up at the end of the summer and routinely fly thousands of miles non-stop through all manner of environmental conditions. John and I agree that a radically novel approach to personal flight is needed, it’s just that we see different ways to get there and that is good. The more people looking carefully at the problem, the more likely we are to resolve it!
My interest is in creating ornithopters of increasing mass and demonstrating their inherent air-worthiness. The engineers at FESTO have been able to realize significant improvements in efficiency with their bio-inspired designs. Digitizing actual bird parts and using a combination of 3D printing and carbon fiber milling is already yielding an increasing diversity of smaller mass flying robots. We have swifts, penguins, hummingbirds and gulls. It won’t be long until other bird families are represented and the employment of artificial feathers should lead to a substantial increase in both thrust and lift generating capabilities. From there, flapping winged fliers will quickly gain mass / size.