Susan King is flying with her father 500 feet above Fauquier County farmland. On his thumbs-up signal, she climbs from the open-air cockpit onto the wing of the 1941 biplane. Fighting hurricane-force winds, she wraps her ankles around a strut and hangs off backward from her knees, waving to the crowd gathered on the ground below.

For the grand finale, King stands on top of the cockpit while her father loops the plane upside-down.

"It's the greatest ride in the world. This is the ultimate," the 37-year-old legal secretary said after landing. "But it takes more guts than most people have."

In fact, the crowd of 60 that watched the wing-walking last Sunday at the Flying Circus Air Show outside Warrenton had other assessments. "I think she's crazy," said her son, Mike King, who was in the crowd. At 17 he is already a pilot, but he said he wouldn't consider riding on airplane wings as a hobby.

"I think that's dangerous," said T.S. Lloyd of Fredericksburg. "She's plenty bold and skilled."

Freckle-faced Nichole Bowling, 11, of Stafford, thought carefully before concluding, "I haven't seen very many people do that."

The wing-walking stunt is one of about a dozen acts put on weekly by the gregarious members of the Flying Circus Air Show in old airplanes that have been refurbished and painted bright colors. The old-time aviation enthusiasts gather each Sunday from May through October on a makeshift airfield near Bealeton along Rte. 644 to reenact World War I dogfights, early air mail pickups, and endless flyover formations to the sound of patriotic tunes.

Air show regulars estimate that only 20 others around the nation practice wing-walking. And King admitted that it takes an unusual blend of strength and nerve to perform in the 150 mph winds.

King said she first got the bug to be a wing-walker six years ago when she saw another woman do the act at the Flying Circus. "I thought, 'If she can do it, I can.' And I started begging my father to let my try."

She recalled that John King, 62, a 20-year veteran of Navy flying and former flight school instructor for United Airlines, said, "Not on your life will my daughter be out on the wing of a plane."

But she persisted, and proved herself by learning to sky dive. "If she has her mind set on something, she'll go to any ends to attain it," John King said.

Starting last summer, Susan King, who is 5 feet 5 inches tall and weighs 125 pounds, began building her strength at a local spa and taking lessons from another wing-walker at the Flying Circus. Ever since, on alternating weekends during warm weather months, she and her father perform in what they believe is the only father-daughter wing-walking team.

"We weren't extremely close before," said King of her father. "Now it's a feeling between us -- I'm counting on him to fly safe and he's counting on me to be careful." She has never tried the stunts with anyone else behind the controls, and she said, "I don't know that I'd want to do it if my dad wasn't flying with me."

Susan King likens the wing-walking moves to mountain climbing, with the key being to take one step at a time. "I'm always frightened," she said, adding that half her fear is from shyness. "If you're not scared, you're not safe. I don't feel or think anything else when I'm up there."

After she first forces her foot out of the open cockpit, King said, she grabs onto the wire cables that run between the biplane's wings and takes six steps toward the end of the wing.

King's first trick is called "skin the cat." Out on the wing's end, she sits down, straps a safety rope around her waist, wraps her ankles around a strut and bends backward to hang from her knees off the wing. Then, to make it look easy, she smiles and waves to the crowd. With a simple tuck of her chin into her chest, the wind against the back of King's neck lifts her in a quick sit-up, then stands and walks back to the center of the plane.

For the last stunt, King climbs without the aid of a safety wire to the top of the plane and straps herself to a vertical brace, tucking her toes under a horizontal bar. Then her father puts the plane through a full loop, complete with a smoke-puff trail, while she stands like a stick atop it.

The King team makes one more low-flying pass to hear the yells and applause from the audience, then lands. After she pops out of the plane, Susan King is approached by a small mob of autograph seekers, while others simply stand in silent amazement at the thought of this mother and secretary taking to the skies on Sunday afternoons.

Susan King gets $50 per act -- high pay compared to the $10 each the ground crew gets, but low for the element of risk. Rides are available, too, for about $25 per person.

Each week, the team metts a rundown hangar for a 2 p.m. briefing before the show. Donning khaki outfits and knee-high leather boots, and clutching caps with earflaps and goggles, their spirits run high.

John King contrasted plush jet flights with the Flying Circus' brand of barnstorming. "Here, people enjoy the opposite of ease and comfort. They like the wind in their face, the low, steep turns."

As they prepare, ringleader C.W. (Tex) Goppert reminds Susan and John King and the others not to get carried away by the fun. "Keep your minds on what you're doing, keep your eye on the weather," the mustachioed man said, "and above all else, don't do anything dumb."