"Think Batman x Iron Man": how pterosaurs are inspiring the next generation of aircraft

Admit it, whatever you drive to work seems a little less adequate now.

Pterosaurophile Mike Habib was recently featured in a Scientific American article about the utility of pterosaur research. Let's face it, as cool as pterosaurs are, it can be hard to justify research into them when the world is faced with real problems like climate change, overpopulation, an enormous biodiversity crisis and Michael Bay movies. But Mike's interest in pterosaurs principally concerns biomechanics, quantifying the mechanical properties of pterosaur anatomy and seeing what it was capable of, and this sometimes allows transference of their evolutionary solutions to our own technological problems. Among other things, pterosaur biomechanics might be applied to some big projects: developing unmanned vehicles - including some which may explore other planets - and developing wind-stable fabrics. The latter may not sound very exciting, but wind-resistant fabrics are essential in all sorts of extreme activities, from exploring remote corners of the world (think tents), lightweight aircraft (parachutes, hang gliders, etc.) and extreme sports (wingsuits).

But that's small fry compared to one idea mentioned in the article. As part of an international team - including myself - pterosaurs may be launching air travel in a whole new direction. The manner in which pterosaurs took off - so called quadrupedal launch - offers a solution to a problem faced thousands of times around the globe each day: launching aircraft into the air as effectively as possible. As we all know, three lines of evidence point to pterosaurs launching quadrupedally, with most effort coming from their forelimbs. 1) animals launch using from their 'default' gait, and pterosaurs were quadrupeds; 2) pterosaur forelimbs are much more developed than their hindlimbs, whereas the opposite is true in hindlimb launchers and, 3) above a certain size, pterosaur hindlimb bones would actually fail in launch (Habib 2008, 2013; Witton and Habib 2010). These point to a powerful, quadrupdal launch mechanic which permitted even the largest, 200-250kg pterosaurs to take to the skies from a standing start, while birds - with their hindlimb launches - are seemingly capped at 70-80kg.

It's not only large birds which look enviously on pterosaurs. Most of our own aircraft require runways for takeoff. Vehicles which can take off without runways, like helicopters, are constrained to large size because of their power requirements and required wingspans. All aircraft launches require lots of fuel, and lots of space. It's unsurprising, then, that quad-launching giant pterosaurs have attracted the attention of engineers, as they clearly evolved a method of launch which is not only space and fuel-efficient, but also incredibly powerful. Practical results are undoubtedly years away, but the notion of a small, solo-pilot aircraft being capable of quad-launch and powered flight is realistic enough that we're seeking money for a project to test the waters. The concept we have in mind resembles a suit more than a plane - as Mike put it on Twitter, "think Batman x Iron Man" - alluding to concepts of the craft being controlled by a person strapped within the chassis, sort of like wearing a multi-million dollar pterosaur costume.

A visual history of pterosaur-inspired flying machines. 1, Ernst Stromer, 1913, basic glider model of Rhamphorhynchus wing membranes; 2, Hankin and Watson, 1914, a model based on their pioneering studies of Pteranodon flight (Hankin and Watson 1914); 3, Erich von Holst, 1957, a rubber band powered, wing flapping Rhamphorhynchus glider; 4, Cherrie Bramwell and George Whitfield, 1974, 7m wingspan Pteranodon glider based on their seminal 1974 paper; 5, Bramwell and Whitfield, 1984, half scale 4.5m wingspan Pteranodon made for the BBC; 6, Paul MacReady, 1984-85, 5 m span Quetzalcoatlus remote controlled, computer balanced glider (see MacCready 1985); 7, Margot Gerritsen, 2005, scaled Anhanguera with fully articulated wings built for National Geographic; 8, Matt Wilkinson, Rodger Highfield, and Vivian Bock, 2007, wind tunnel model of Anhanguera used to test Wilkinson’s hypotheses on pteroid orientation, 9, PteroFlight, our new project looking into pterosaur wing performance and its applications. Image compiled by Iain McCreary, used with permission.

What might such a thing look like? Sadly, it's not going to look like the thing at the top of this post. What you've got there is food for thought rendered by someone who's aircraft design skills boils down to watching science fiction movies, and who's engineering protocols are determined by Cool Points. It takes the idea of a 'pterosaur exoskeleton' to an extreme definition, right down to the limb proportions, wing folding and ability to walk about on all fours. Undeniably cool looking, just not very practical. But technologies and ideas taken to an extreme in this painting actually do exist. Augmentation of human frames with robotic exoskeletons is an intensive area of research and already employed to aid physically disabled people, as well as boosting the carrying strength of ground troops. Computers capable of flying deliberately unstable and responsive aircraft -manned or unmanned - are widely utilised. Large, controllable pterosaur-inspired vehicles with moving, adaptable wings have been researched for 100 years (above) and achieved flight (albeit not launch) on numerous occasions, with recent models featuring automatic computer control. The basic elements of this project - essentially a computer-supported, pterosaur-inspired lightweight flying exoskeleton - are at the far end of known technological spectra, not fantasy and hokum.

Of course, we're not going to see pterosaur-inspired suits catapulting people skywards tomorrow. Some serious research and developmental work is required before we see anything like a working concept or even - if we're honest - if it's possible at all. At this stage, however, this ultimate application of pterosaur research is not being ruled out. In other words, keep watching the skies - and check out Mike's Scientific American feature for more details.

References

• Bramwell, C. D., & Whitfield, G. R. (1974). Biomechanics of Pteranodon. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences, 503-581.
• Habib, M. B. (2008). Comparative evidence for quadrupedal launch in pterosaurs. Zitteliana, 159-166.
• Habib, M. (2013). Constraining the air giants: limits on size in flying animals as an example of constraint-based biomechanical theories of form. Biological Theory, 8(3), 245-252.
• Hankin, E. H., & Watson, D. M. S. (1914). On the flight of pterodactyls. Aeronautical journal, 324-335.
• MacCready Jr, P. B. (1985). The great pterodactyl project. Engineering and Science, 49(2), 18-24.
• Witton, M. P., & Habib, M. B. (2010). On the size and flight diversity of giant pterosaurs, the use of birds as pterosaur analogues and comments on pterosaur flightlessness. PloS one, 5(11), e13982.