"On a good day we could fly forever," I replied, "but with those cirrus clouds diluting the sun, we'll be lucky to get 15 minutes." We watched Buck spiral down in the Piper Super Cub and drop the tow rope before landing.
"Buck's a bit of a legend around here," I said. "He flew a Schweizer 1-26 from here all the way to St. Louis."
"Lafayette to St. Louis in a glider? That must be 200 miles."
"Sounds about right - took him six hours, I understand."
"How could he stay up so long?"
"If only this were a better soaring day, I'd show you." Noting a 200-foot-per-minute descent on our variometer (a sensitive rate-of-climb indicator), I directed Larry toward a nearby smokestack. "Hope you don't mind the smell of soybeans," I continued. "Maybe we can find some lift over the factory parking lot."
Sunlight heats not the atmosphere, but the ground, which in turn warms air above it. Surfaces like asphalt and dry dirt fields radiate heat, while forests, lakes, and cornfields absorb it. As a result, columns of air rise from warm surfaces, while all around them cooler air sinks. Sunlight powers it all, and therefore our glider.
"Those rising columns of air are our soaring tickets," I said. "'Thermals,' we call them. Often on clear days cumulus clouds form on top."
"You mean like that one, Greg?" Before I could look, the left wing rose ever so slightly.
"I've got the controls!" I said, lowering half flaps and banking sharply into a left turn.
"What's happening?"
"That rising wing indicates a thermal. They're cylindrical, and I'm turning to center us in it. Look at the variometer." For the first time, the instrument showed a climb instead of a descent. With a "whoosh" our stomachs dropped, and we began rising like an elevator.
"Greg, we're climbing at 1,500 feet per minute - without an engine!" Surprised at the thermal's strength on such a day, I looked up. The cirrus layer had unexpectedly retreated from the sun, replaced by scattered cumulus.
"Each cloud caps a thermal," I said, "like a balloon on a string."
"How high can we go?" shouted Larry, elated.
"To wherever the lift runs out, short of the clouds themselves. Then you make a beeline to the next thermal and climb again. 'Cloud streets,' we call 'em. That's how Buck made St. Louis. In flat country like this, it's the only way for sailplanes to climb.
"You mean Buck circled like this for hours on end?"
"That's right. Altitude is traded for distance cruising from one thermal to another through areas of 'sink.' Then you must climb again by thermaling."
"What if you run out of lift?"
"Then you land in a field, haul out the glider, and try again another day. It happens less often than you might expect," I said.
"How did Buck get back from St. Louis?"
"That's a little less glamorous. His wife followed him by car, and they trailered the glider back."
Soon all was silent except for the gentle whistling of cabin vents, whoosh-and-wheeze upon entering each new thermal, and an occasional few words when swapping controls. I thought of my first glider flight in an aging Schweizer 2-22 marked with red lightning bolts. Hangars being in short supply, the beast resided in half a stall, meaning the wing had to be reattached each day before flight. Although notorious for poor glide performance, the 2-22 was docile and a good teaching machine. Those who learned to find lift in it could climb like rockets in anything else. Like a homely dog, that glider had character, and we soon learned to love it. Today's Blanik, however, was a far more capable soaring machine.
"Look!" said Larry. "Birds flying formation with us!" Three hawks banked shoulder-to-shoulder off our wing, sharing the same column of rising air. That wonderful, lazy afternoon soared on forever to the tune of whoosh, swish, and bank. We climbed, swooped, and then climbed again. Not until bladders pressured us did we consider coming down. Gently I applied spoilers to kill lift over the wing, but even when fully extended they showed no effect in bringing us down. Only when I kicked rudder and sideslipped did we finally descend from our rightful place with the birds. We landed to discover the towplane lodged in its berth, and Buck long gone.
"I had no idea we were up for so long," said Larry, checking his watch. Unwittingly, we'd flown for three-and-a-half hours, climbing repeatedly as high as 6,400 feet. Not bad for an engineless aircraft over flat Indiana farm fields. Odd how our flying carpet had transported us so far from Earth, yet covered no physical distance in the process. Today's destination had been simply the pure joy of flight itself.
>Greg Brown was the 2000 National Flight Instructor of the Year. His books include The Savvy Flight Instructor, The Turbine Pilot's Flight Manual, and Job Hunting for Pilots. Visit his Web site ( www.gregbrownflyingcarpet.com ).
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