October 2, 2003
the "Sweet Spot"
It's about 1228 statute miles to Chassahowitzka NWR where the new Eastern flock spends winters. By bird standards, that's not so long a migration. But when you mix ultalight aircraft and birds together, the time stretches to nearly two months of travel. That's because each is more efficient without the other.
But the mix of birds and ultralights is a necessary one, at least for the chicks' first journey south. And flying with the plane CAN be of benefit to a whooper, particularly the lead bird closest to the wing. That's because the ultralight acts as lead bird, and the wing creates lift that gives the nearest crane an easier ride. That means the bird can soar more and flap less. Have you ever seen the wake created in the water behind a speedboat? You could surf on that wake. Wings create the same type of "wake," but with air instead of water. Because the ultralight is so slow and has a large wing, it creates a large wake. That's why pilots say the "sweet spot" is the position closest to the wing. Up to to six cranes can surf on the wake behind the trike's wing, and the lead bird flies only 6 to 8 inches from the wingtip!
In this audio clip (67 seconds), pilot Deke Clark talks about this question:
Try This! Journaling Questions
refers to the "V" formation or chevron-shape flying formation
in this audio clip. Draw a picture that illlustrates this.
For more, see our in-depth lesson: How Birds Fly.
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