No Go. Warming Air + Headwinds (+0 Miles)
November 13, 2009: Migration Day 29

Learn more about the pilot's helper, the GPS, in today's lesson.
Photo by Chris Gullikson


South winds are again blowing warmer to Stopover #5. The temp will rise to a balmy 60 degrees F later today with gusts to 20 mph. Aloft the SSE winds are ripping along at a powerful 35mph. Warm + windy = no go.

But today is a good time to appreciate the GPS units in the ultralight planes. Imagine if the pilots hadn't had the benefit of the GPS in making their decision to turn back on Day 27! Joe wrote: "We slowly climbed to 700 feet and watched as the ground speed dropped to 17, then 15 miles per hour. The GPS gives you the time-to-destination in hours and minutes. We took off with 2 hours to go and now, after flying for 30 minutes, the next stop was 3 hours, 20 minutes away. We only carry enough fuel for 3 and a half hours so it was obvious we were not going to make it."

In the Classroom

  • (a) "Air speed is the velocity of the aircraft through the air, says pilot Joe Duff. "If you go too slowly the wing cannot generate enough lift. At the same time, the air through which you are flying is also moving. Think of a speed boat going upstream in a river. It may be cruising at 50 mph though the water, but if the water is flowing downstream at 20 miles per hour, the boat is only passing the shore line at 30 mph. In the air that is called ground speed, or the actual speed you are passing over the surface. On our flight two days ago, the birds were eagerly flying along at 38 miles per hour air speed, but only making 25 mph ground speed. What speed was the headwind?
  • (b-for-bonus) Click here to study the photo of the GPS unit pilot Chris's ultralight on Day 42 of last fall's migration. The photo gives us a snapshot of the exact moment it was taken during the flight. What information did the GPS give Chris at that moment? Answer the questions to find out.

Journey North is pleased to feature this educational adventure presented in cooperation with the Whooping Crane Eastern Partnership (WCEP).