MOUNT PLEASANT - The jet's turbine engine spun up, the noise rising to a whistle and then a soft roar as the odor of burning kerosene flowed across the flight line. It taxied out, turned, then rushed forward and climbed into the sky, all while pilot Roger Olsen stood on the ground.

Welcome to the modern world of radio-controlled airplanes - not the small things that once sounded like giant, angry wasps but aircraft driven by gas engines with mufflers, by electric motors or kerosene-burning turbines that cost thousands of dollars.

Smaller piston engines burn a combination of oil, alcohol and nitromethane, said Ron Dixon, who is 74 now and started flying model planes when he was about 10.

"The big ones burn gasoline," he said, pointing to a large, yellow plane during a walk among the tents on Sunday at the Racine R/C Club's flying field in Mount Pleasant. These larger engines burn a gasoline-oil mixture like that used in chain saws and produce 6 or 8 horsepower. Some are half-scale planes, Dixon said, meaning they're half as large as the real thing.

But gasoline is no longer the only option.

"I flew gas back in the 1960s and '70s," said Dennis Vollrath. Now his planes are all electric with no fuel to mess with or to make a mess all over him and the plane. He pointed to one model which he's tracked at 90 mph. Battery technology - lithium ion or lithium phosphate - means smaller, more powerful sources of power for the lightweight electric motors. The squarish batteries weigh about a half-pound each and are slightly larger than the cardboard tube at the center of a roll of toilet paper.

"Two of these will start your car. That's how powerful they've gotten," he said.

After flying his twin-motor electric plane, Aaron Cochran attached a small video camera under one wing of his Radian sailplane. A folding propeller mounted on an electric motor allowed him to launch the sailplane and get it to an altitude where he could turn the engine off and let the plane ride the air currents while the camera shot pictures of the ground. He intended to upload the video onto the Web site YouTube. (You can find such videos by searching "radian" on http://www.youtube.com)

Like other people at the field on Sunday, Cochran, 49, an engineer who lives in Brown Deer, became interested in radio-controlled planes when he was a young man and saw one flying above his home in Glendale.

Getting started today costs only about $500, said Cochran and Vollrath. That will buy a decent plane and the control units. Beyond that there's plenty of free advice at clubs.

"Then we get down to the real money," Dixon said as he approached the sleek gray jet owned by Roger Olsen of Oak Creek. "That's a pure jet turbine … about 200 miles per hour."

The jet body costs a few thousand dollars. A turbine engine producing about 25 pounds of thrust costs about $4,000 more.

"There is no really cheap way to get into jets," Olsen said. He has his eye on a replica of the Air Force A-10 attack aircraft. It has an 8-foot wingspan, and he'd have to buy two engines.

And there was still work for him to do when the plane arrived from the manufacturer. He had to install the circuit boards, wiring and put the fuel lines in place to move the gallon of kerosene from the fuel tank to the engine.

"I had to install the servo motors, the landing gear. Now I have to find out why the brakes didn't work."

When his jet glided down from its 7-minute flight, the plane rolled farther than it should. Fortunately the friction of the grass on the 800-foot runway helped bring it to a halt. But he won a round of applause from the spectators who complimented him on how well he handled the plane in flight.

The Racine R/C Club has about 70 members, said Jerry Rose, the club vice president. A look across the field on Sunday showed that the people out flying tend to be middle-aged or older.

"We would love to have some young kids starting," Rose said. Several club members are qualified to teach people how to fly the small planes using dual-control boxes that allow an instructor to override a student's controls if necessary.

Kent Buska, 12, has every intention of learning. He lives in St. Croix in the U.S. Virgin Islands and was in town to visit family. His uncle, Keith, who also flies radio-controlled planes, brought him to the club.

"I'm going to get that one right there," Kent said, pointing to a box for a model of the Air Force's new F-22 Raptor fighter, but a slower model driven by a piston engine and a propeller.

Flying model planes teaches you many things, he said. One learns mechanics, aerodynamics and, of course, how to live within a budget.

Then the sky's the limit, at least the first 400 feet of it. Above that model planes can't fly, but that's still plenty of room for fun.

ABOUT THE CLUB:

The Web page for the Racine R/C Club is http://www.rc.freehomepage.com. You can see people flying at the club's field on any day, winter or summer, rain or shine. To reach the field, from Highway 20 turn north on West Road. Just before you reach the gate of the Mount Pleasant Compost Site, you'll see the flying field on the right.