We flew to Rantoul, IL today -- home of the Chanute Air Museum, on the site
of the former Chanute Air Force Base. The wind was predicted to be
howling -- winds aloft were calling for 54 knots at 6000 feet! -- but the
sun was shining, and we were enjoying our first Saturday off since last
Oshkosh. So off to Rantoul we went.

Our local AWOS was calling the wind 180 at 13, gusts to 21 -- strong, but
right down one of our three runways. Takeoff was a non-event, and the cool
temperatures meant we were soon climbing out at 1200+ fpm, even with 84
gallons and four aboard.

As we passed through 500 feet AGL, we experienced some moderate turbulence,
followed by some really "hinky" air -- you know, the kind that lifts first
one wing sharply, then the other? It's an almost uncontrolled feeling,
where you really just kind of keep things pointed in the right direction as
you climb through it.

Then, the most amazing thing happened. Our ground speed, which had been an
anemic 90 knots or so climbing out in a shallow "cruise climb", suddenly
accelerated sharply. Within seconds, we were doing 130 knots climbing on
the SAME HEADING that had given us a headwind just moments earlier!

Interestingly, the air instantly became silky-smooth, with hand's off flight
producing an absolutely rock-solid heading. As we leveled off at 5500
feet, our ground speed rapidly climbed through 170 knots, meaning that we
had a solid 30 knot tailwind, heading South. As we passed Muscatine, the
smoke from the power plant clearly showed a wind out of the South, yet at
5500 feet we were riding a strong tailwind from the North.

On the way home, Mary stayed down below 3000 feet, where the headwind (it
was no longer out of the South down low, dang it) was considerably less. We
still dragged home at 117 knots, meaning we were bucking a 25 knot headwind.
The one time ATC asked us to climb to 3500 for radar coverage, we instantly
lost 25 knots in ground speed!

Again, the air was smooth as glass, however. It's hard to envision an air
flow that could cause such severe wind shear, yet not also cause moderate to
severe turbulence.

Never seen anything quite like it.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"