The first thing you notice is the smoothness: the two 12 1/2 foot rotors are whipping around at 500 rpm - 435 mph at the tips - and the gizmo is hanging about a foot off the ground. A little noisy, but so cushioned: floating on air. The blades of grass are diving for cover in the slipstream underneath you and then - WHIIISSSSSSSSSSS - the thing slides forward at 45 miles an hour, slips over a river bank almost kissing the water, and then arcs up gracefully at 800 feet per minute. In 40 seconds you've traveled half a mile only to stop in mid air, hovering over a tree at 500 feet, staring down like a bird.

B.J. Schramm was dreaming about birds in the early 50s when most kids his age were listening to Johnny Ace crooning "Pledging My Love" on the radio. He was in high school then, fascinated by stories about James Bond-like military plans to design a one-man collapsible helicopter that could be dropped behind enemy lines in Korea.

The Army lost interest. Schramm never did. By 1958 he had made a personal commitment to the development of a personal helicopter for use by anyone. He's sold about a thousand prototype one-seaters, and next month he opens his first. Sky Center here near Phoenix, a training complex where people will learn to build and fly the Scorpion 133, a two-seater helicopter with a 120-mile range that sells for $13,500 - less than many Porsches, MErcedes, BMWs and Cadillacs.

The price includes flight training, and Schramm's RotorWay Corporation is already booked for a full year with 20 people a week signed up to start flying.

"You go up to one in five people on the street and you'll find an interest in the romanticism of helicopters," Schramm says. "Certainly the Vietnam War indoctrinated people about helicopters. They think only rich people can afford them, but we're trying to make helicopters for the little guy."

It has taken Schramm 18 patents and 19 of his 39 years to get this far. His family - dairy farmers from Arcadia, Wisconsin - thought he was crazy to keep at it, particularly after he flunked a course in airframe construction at Pasadena College. He hustled his relatives and friends for money. He sold encyclopedias door to door and worked as a machinist to support his habbit. He spent three years just designing a rotor system that could get up to speed without distintegrating; another five to get the thing to fly through a tight circle. He started using outboard marine motors as a power plant, tried adapting a VW engine to the craft, and wound up manufacturing his own water-cooled engine from scratch.

The films are gone now, burned in a warehouse fire, of the day Schramm's dream machine finally flew. He was living in LA then, and had driven with a friend four miles into the dessert, to the EI Mirage dry lake, because no airport would let his screwball, home-made flying egg-beater near the place.

"I taught myself to fly the thing," he says. "I didn't have a license then; I couldn't afford to get one. I got about six inches off the ground and probably flew less distance than the Wright brothers at Kitty Hawk. When I put down, I threw my helmet up in the air about 50 feet and ran around the craft like a crazy man in hundred foot circles."

As slow as the progress was, Schramm kept believing in helicopters as a mode of personal transportation. Maybe it was growing up in the 90s: all those pictures in comic books that depicted the skies of the future killed with little transport devices - the same pictures that used belching smokestacks as a symbol of progress and had cloverleafs and four-lanes down below uncluttered with streamlined vehicles guided by electronic sensors.

But just as the smokestacks were legislated to stop belching, and the electronic cars never became a reality, helicopters have not exactly become a household item; there are only 5,500 non-military choppers in the entire United States, according to Rotor & Wing magazine.

Schramm plans to change that - radically. He's already quick to point out that about one-fifth of America's private helicopters were sold by his company in the last six years, and that next year the total fleet will be increased about 18 per cent, solely by RotorWay Scorpions.

"You're not seeing the helicopter used in mass," he says, "because there's no training program for the average guy. You're talking about a minimum of $100 an hour just to rent a trainer, then $40 for the instructor, not to mention that the cheapest thing you could buy until the Scorpion came out cost $65,000. The market is virtually untapped, because there isn't anybody who has the same idea as us."

Of course, there may be another reason: The helicopter is a mechanical contrivance. It has no dynamic stability. It just hangs from a shaft. It doesn't want to fly (unlike a fixed wing plane, which constantly seeks a flying attitude). The pilot has to fly in, and he has to know how it works - intimately.

"It's like a musical instrument," says Schramm. "The musician has to know how to tune it. The mechanic and the pilot usually make the helicopter work together. In a private helicopter you have to compress the two."

So RotorWay's plan is to have the buyer build the craft himself.

"Giving the individual the opportunity to build the craft allows us to teach the owner to be his own mechanic. Twenty-five per cent of the cost of a Bell helicopter is for product liability insurance. We won't sell it to you put together because the individual is really the manufacturer and this way he bears the responsibility. We don't want to have to charge an extra 25 or 30 per cent to protect ourselves from you.

"I'm not interested in selling every Tom, Dick and Harry a helicopter. I know P.T. Barnum said, 'I don't care what they're saying about me as long as they're talking about me.' But I don't feel that way. I may never be a rich man, but I think you have to use good sense in these things.

"We just won't sell to anyone. We've gotten inquiries from police departments, and we tell them to get a Hughes 300. We make people home out here, and we talk to them before we'll sell them one. Forget about taking off from a subdivision or a big city. But if you have an acre and your neighbors don't mind, you can take off from your backyard."

Which is not to say that, in fact, the helicopter could not become a common mode of transportation in the future. The Federal Aviation Administration and the Metropolitan Police put no limits on flying around Washington, for example, except to note the restricted airspaces around the White House and the Capitol Building. While fixed-wing aircraft are required to maintain certain minimum altitudes, helicopters can go as low as they can be controlled safely, which is roughly 50 feet above the ground.

"The whole purpose of owning a helicopter is so you can stay away from controlled airports," says Schramm.

The people who will start arriving at the Sky Center on April 15, according to Schramm, are about as varied as can be imagined. "If you could have asked Henry Ford who he was selling Model Ts to, I'd tell you the same people," Schramm says. "A farmer. A construction contractor. A mailman. A large corporation executive. A man who owns three Jet Rangers ($250,000 Bell helicopters) and wants a Scorpion to play with. The only people absent from the group are really low-income bracket people. And there aren't that many people from heavily populated areas. It's basically folks who want them for recreation. They see our ads and get intrigued with the freedom of helicopter flight."

Schramm has an intense but almost bumbling quality about him that suggests the stereotype of engineer of absent-minded professor. He's a dreamer in wash-and-wear clothes: no flash, just work. He's vaguely aware that his ideas might have some effect on the future of human transportation, he's much more fascinated by the mechanical thing than the idea.When he was a kid he stuck a propeller on the back of his wagon. A few years later he borrowed the engine from the family lawn mower to build a go-cart. His office is littered with trophies won at dune buggy races. He has plans to open Sky Centers soon in Texas and somewhere on the East Coast, but he seems more interested in talking about the problems of designing and casting your own engine, and how the company developed a tiny little gasoline motor that powers hand tools in order to work the bugs out of the 133 HP Scorpion engine.

He'll also tell you how it's impossible to just dump a kit on somebody; how you have to space it out and teach buyers every step of the way on both the building and the flying end; how it takes at least six months and a good knowledge of welding to put the craft together; and how four people who didn't have much training crashed prototype Scorpions and were killed.

But Schramm, in his quiet way, is a proud man.He wanders around the factory, and singles out some of his 100 employees for pats on the back. He frequently says that whenever he's done has been "with The Lord's help."

But beyond all this, B.J. Schramm seems most at home inside the Scorpion, even though his 6' 2'' frame barely makes it in.

He knows the art of flying that's involved. A slight twist on the throttle makes fine adjustments in the rotor speed. The foot pedals edge the craft slightly to the left or the right with small movements; heavier pressure puts it in a fast turn. The center stick points the ship up or down; the cyclic control adds forward movement.

But hovering is the real test. The feet, the two hands perfectly coordinated, hanging the chopper in a perfectly still attitude at any altitude. Constant monitoring of the controls is required and that is what helicopters are all about. Below, a few robins flutter across a patch of trees, and the great dream of Icarus is recalled: wax and feathers for the gift of flight.

What would Icarus think of the Scorpion?

The engine uses regular gasoline, and the craft can be landed right in a gas station - if it's big enough.

Otherwise you can land it on the side of the road, stick the ground handling wheels over the struts and push the well-balanced 800-pound vehicle up to the pumps.

"It causes a lot of heads to turn," says Schramm. "We're looking forward to the day when it won't cause any consternation." CAPTION: Picture 1, B.J. Schramm stands with his brainchild, the Scorpion 133 two-seater personal helicopter, Photo by Tom Zito; Picture 2, The purchase price ($13,500 includes flight training, but the craft must be assembled by the customer.; Picture 3, Jack Dickerson of Forestville, Md., takes his personal chopper up for a spin. By Gerald Martineau - The Washington Post