Building a Better Aircraft

That Renaissance mastermind -- Leonardo Di Vinci -- apparently was onto something when he set about trying to design an airplane. Take a look at reproductions of Di Vinci's drawings and diagrams and you'll notice that his idea of manned flight was actually "winged flight". 'Ol Leonardo understood that "flapping" is really where it's at when it comes to manned flight and aerodynamics. Unfortunately, Leo could never overcome the problem of weight differential, meaning that a human could never flap the wings of his contraption fast enough to get off the ground, much less maneuver in the sky.

Fortunately for us -- several hundred years later -- aerodynamic engineers are finally realizing that Di Vinci's theories about flight are pretty well-grounded (pardon the pun). Namely, that "natural flyers" like birds, bats and insects outperform man-made aircraft in aerobatics and efficiency. In fact, according to a 9 Feb 2008 article on ScienceDaily.com, a team of University of Michiganengineers are studying these animals as a step toward designing flapping-wing airplanes -- although with wingspans smaller than a deck of playing cards.

It's really just a matter of common physics. Consider this: a Blackbird jet flying nearly 2,000 miles per hour covers 32 body lengths per second. But a common pigeon flying at 50 miles per hour covers 75. The roll rate of the aerobatic A-4 Skyhawk plane is about 720 degrees per second. The roll rate of a barn swallow exceeds 5,000 degrees per second. Or how about this: select military aircraft can withstand gravitational forces of 8-10 G. Many birds routinely experience positive G-forces greater than 10 G and up to 14 G.

Wei Shyy -- who chairs the UMich Aerospace Engineering Department and is the author of the new book "The Aerodynamics of Low Reynolds Number Flyers." Feels that, "...Natural flyers obviously have some highly varied mechanical properties that we really have not incorporated in engineering..."