Something valuable and close to irreplaceable went out of the world when they began herding 100 people into a Concorde and flying them across the Atlantic faster than the speed of sound. "It's a way of getting there with a crease in your pants," admits California businessman Dell Riebe. But, to him at least, it's not what flying -- real flying -- is all about.

For Riebe, flying means cranking up his 1938 J3 Cub and soaring over the foothills of the Sierras. The craft is so slow and so stable that a person has little to do in the air but admire the scenery. And the scenery around Grass Valley, the tiny town in which Riebe lives and works, is admirable indeed: the snow-covered Sierra Nevada to the east, the low-lying San Joaquin Valley to the west, with the Coastal Range and the Pacific beyond. Glinting arroyos wind through the deep canyons, and stately ponderosas cast purple shadows on the red, iron-rich earth. If a man cannot rekindle his spirit flying over surroundings like these, he is truly lost.

Which explains why Dell Riebe closes the door on his $2-million auto parts and truck accessory business on occasion -- often on the spur of the moment -- and heads for the Grass Valley airport, five minutes away. Frequently, he is accompanied by his friend Chuck Yeager, the legendary pilot who first broke the sound barrier in 1947. Yeager has flown over a hundred different types of military aircraft, and Riebe and Yeager together have logged nearly 20,000 hours in the air. Yet the J3 Cub they mess around in represents flying at its best -- certainly as it used to be, in a simpler, less congested time.

"Whenever I get bored at work or want to get away from people," says Riebe, "I jump in the plane and go flying. I head down-country, land in a pasture, get out, have a cigarette, and listen to the cows, or sit on the wheel and look at the deer."

Landing in pastures takes a degree of experience, Riebe concedes." You can land uphill, which gives you a short landing roll, get out, turn the plane around, and take off downhill, which gives you a short-take-off roll. It all depends on the wind and the temperature of the air." Mishaps can occur, however. Some years ago, for example, while flying up a canyon in bad weather, Riebe noticed the walls closing in.

"I took sight on a little clearing," he says. "I set her down, waited for the weather to clear, and flew out the same way I came in. But that's the way a lot of people get killed: getting into a places where they can't turn around. They wind up in the wall somewhere."

Since the Cub's 85-horsepower engine tops at 65 miles an hour (burning 4 gallons an hour) and its range is approximately 180 miles (its fuel tank holds 12 gallons), trips are confined to nearby areas. Even so, a 30-mile trip to Marysville, a favorite breakfast spot of Riebe's located in the San Joaquin Valley, can result in what he calls "Cublag." Not a plane designed for cross-country travel, he says. "It's cramped, cold in winter, and hot in summer, unless you open the side and let the breeze blow in."

Riebe is partial to tail-draggers like the Cub, with its old-fashioned landing gear and tiny wheel at the back. "They're low-cost aircraft," he says, "and they're easy to maintain because they haven't got retractable landing gear and constant speed props and things like that. The J3 doesn't even have batteries, which means it has to be hand-propped."

Riebe's experience in tail-draggers began in 1935. "I was driving a truck at the time and flying for fun," he recalls, "but pretty soon I began flying full-time. If a fellow wanted to go to Billings, Montana, I'd ferry him over. And if he wanted a ride back, I'd sit in the plane and wait for him to finish his business. Sometimes two of us would go bounty hunting. We'd open up the side of the plane and the gunner would sit in the back with a shotgun. Whenever we saw a coyote, the guy in front would put the plane into a forward slip in order to let the guy in the back get a clear shot under the strut. The sheep association paid us five dollars for a pair of coyote ears in those days."

With the advent of World War II, civilian aviation came to a halt within 150 miles of the Pacific coast. "They were worried about Japanese planes," Riebe points out. "It was easier to monitor the air if there weren't any U.S. planes flying." Riebe became a civilian instructor and later a flight officer with the Air Transport Command. He flew everything from P-38s to B-17s.

Shortly before leaving the service to return to civilian life, Riebe met Yeager at Edwards Air Force Base. "He was in the rocket program at the time," Riebe remembers. "He was building up to the penetration of the sonic barrier. He'd had quite a combat career, including one day when he shot down five German ME-109s. He caught them like a covey of quail, grouped just right."

Some 30 years later, Yeager stopped by Riebe's store and the two men got to talking. By then Yeager had retired from the Air Force and was living in nearby Cedar Ridge. "We got along right away," says Riebe, "because of our flying backgrounds and because we're not social people. We're not too good at parties and small talk. We enjoy being by ourselves. We can ride to San Francisco together and not say five words."

Because their dispositions were perfectly matched, the two men soon took to flying together, rolling out the yellow J3 and cranking it up for an hour or two in the sky. "Yeager and I do the same thing," says Riebe. "We get a little itch to go look at something -- I want to look at a piece of land or he wants to look over a spot he plans to quail hunt -- and we'll jump in the plane and go. But sometimes we don't have a purpose. We'll just fly and have no thought of where we're going. We just take off, aim the plane, and see what happens. Then we sit back and relax and think our own thoughts."

For Yeager, there's no problem in switching from supersonic aircraft that travel at more than twice the speed of sound to an aircraft so slow you can crash it into a dense patch of oak trees and walk away. "Flying is a series of trained reactions," he says, "same as driving. Like the guy that parks cars for you. He never makes a mistake, whether he's driving an automatic or a manual transmission. Same with flying different kinds of aircraft."

Compared with many of the aircraft Yeager has flown, Riebe's J3 is the equivalent of a Model T: no rudder trim, no propeller positions, and when the little wire attached to the cork float in the fuel tank disappears from view outside the windshield, it means the tank is empty.

Simple as it may be, however, the J3 is a classic: One sits in the Smithsonian along with "Glamorous Glennis," the X-1 Yeager piloted through the sound barrier. And the J3 offers certain advantages supersonic aircraft don't. "When you're smoking along at 40,000 feet in a P-80," says Yeager, "you see nothing on the ground. But when you fly over this country at 500 feet, there is always something new to look at."

And because Grass Valley is not located near a positive controlled air-space where traffic controllers are working high-density air traffic, Riebe and Yeager never file a flight plan. "We wouldn't anyway since we're never really going anywhere," says Riebe. "To have a flight plan you have to have a destination. But if you have no destination, you just up and fly."

"And that," says Yeager, "is what I call fun flying."