Friday, November 15, 2013

Flight


I love things that help me get a new perspective on the world, so I always request a window seat. Taxiing to the runway, my face pressed to the clear plastic window, I watched a flock of snow buntings swoop in unison above the grass. White flashed on their wings. There was grace in the unconsciousness of their flight.

Birds are so well adapted for travel through the air that their movements can seem effortless. Even when we see how hard they are working, the power in an eagle’s wings and the skill of a hummingbird’s maneuvers fill us with a sense of awe. Human-designed flight was not so easy.

In the years since Icarus flapped his waxy wings toward the sun in ancient Greek mythology (and fell into the ocean when they melted), humans hadn’t had much luck trying to copy birds. Paradoxically, the great success in human flight came when we stopped trying to mimic natural flyers and began designing from scratch, says Professor Spedding, of the University of Southern California.

Now there I was, ready to take to the air, casually fulfilling the dream of flight with millions of other people today. We turned down onto our runway and sped up. As the force pushed me back into the seat, I imagined what it must be like to be a loon – running hard across the lake, splashing and pushing with broad feet, until finally achieving enough speed for liftoff. Even when I was no longer jostled by the bumps of earth, I was still pressed back into my seat by the acceleration.

Loons have the heaviest wing-loading of any flighted bird, so they, like airplanes, must gain speed in order to generate enough lift to leave the ground. They must maintain that speed, too, or risk a crash landing. Have you ever seen a loon fly slowly? Me neither. Also like commercial airliners, loons need their wings mostly for long-distance trips, and use wide-open spaces for take-off and landing. This allows both planes and birds to survive with limited maneuverability.

I’m likewise fascinated to see a bird’s-eye-view of the landscape – to follow familiar rivers, highways, lakeshores and forests in an effort to understand them from a new perspective. Today, however, my view was blocked as we rose through a thick layer of bright white clouds.

Thankfully, the pilot has a sophisticated instrument panel that helps guide our course. Birds, too, have a sophisticated set of tools for navigation. Besides using landmarks during the day, they use the rotation of the stars, the orientation of earth’s magnetic field, and the angles of polarized light at sunset.

New research from the Max Planck Institute for Ornithology in Seewiesen, Germany, has added weight to the hypothesis that homing pigeons (and probably other birds, too) use smell to navigate home. Every place smells a little different, and breezes coming from different directions carry that information to the pigeons. The birds can essentially create a smell map in their head that helps them navigate back home. Amazing! But I’m still glad my pilot is using a GPS.

Although humans only achieved flight when they stopped trying to copy birds, now that we’ve figured it out, engineers are looking back at the more experienced flyers to solve all sorts of problems. For example, jet aircraft engines used to “choke” at supersonic speeds due to air moving around the engine instead of through it. The peregrine falcon – which can dive at over 200 mph – provided a solution. Specialized cone-shaped bones near its nostrils, called baffles, deflect shockwaves of air and allow peregrines to keep breathing. Jet engines now have similar cones in their engines.

Despite the clouds, we found Chicago, and with our loon-like limited maneuverability, swung wide over the lake to start the landing pattern. As we slowed down to land, the plane used another bird-like feature on the wing. Nearing the ground, slats on the front of airplane’s wings dropped down. According to Wikipedia, this “allows the wing to achieve a higher than normal angle of attack – and thus lift – without resulting in a stall.”

On a bird, the alula--a small projection on the leading edge of the wing--serves the same purpose. It is essentially the bird’s thumb, and its three-to-five feathers can be moved freely. When flying slowly or landing, the bird can move the alula slightly upward and forward, giving it the same advantages as the airplane slats in slower or higher-angled flight.

Future airplanes may use a sharkskin-like paint job or butterfly scale-like coverings to reduce drag. Seabird-like moveable wings might improve efficiency with gusts. Humans continue to look to nature for more ways to improve our flight. Even rubber made from Kazakh dandelions may one day provide a more sustainable material for landing gear.

As the old-fashioned rubber tires bumped onto the runway beneath me, I was grateful for the chance to view the world from a new perspective. But I realized that my relatively effortless trip was made possible by years of innovation – just like the snow buntings’ effortless grace came only after eons of evolution.

For over 45 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI, at 13470 County Highway M. The current exhibit, “Deer Camp: A Natural and Cultural History of White-tailed Deer,” opened in May 2013 and will remain open until April 2014.

Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Discover us on Facebook, or at our blogspot, http://cablemuseumnaturalconnections.blogspot.com/.


1 comment:

  1. I am always like to travel through flight. But still i did not get that chance. But it will happen soon. Thanks for sharing useful information. Website Designers Bangalore

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