The cars collided head to head on what they call the Dover Dips, on the highway leading from the family farm in Middleburg, Va. She felt an electric shock run through her body. "I've broken my neck," she told the men who came in the ambulance.

She was 21 when it happened, and life then looked like a royal flush, the way it usually does at that age and the way it does particularly when there is background and money, and a love for the steeplechase and a job in the Kennedy White House.

At first, the doctor said she'd be skiing the next winter. She stills resents him for that. Months later, the nurse had a question. "Now, Phyllis dear, have you thought about spending the rest of your life in a wheelchair?"

Phyllis, then Mills, now Wyeth, had thought a great deal about that. It is clear, as she walks across the room with her crutches, that she decided against it.

"First I thought, 'Well, Roosevelt ruled the world from his wheelchair, I can take care of myself in mine,'" says the 38-year-old vice chairperson of the National Committee, Arts for the Handicapped. But there were drawbacks. "All the worst creatures come to speak to you at parties, and there's no escaping them."

Sunlight fills the Watergate apartment, falling on the raucous daffodils that came from the family farm in Pennsylvania, and the austere beauty of the quince blossoms, brought by hand minutes ago by an admirer of the work of her husband, artist Jamie Wyeth.

Candor and wry humor fill her eyes as she talks about the National Very Special Arts Festival that has brought hundred of handicapped children and artists of all disciplines to Washington this weekend.

Her gray-gold hair hangs loose around her shoulders and she is dressed for spring in soft fabrics and flower print. Her voice is fueled with a warm intensity that contrasts sharply with the five pound, cold steel brace that surrounds her leg and the soft blue shoe. "I don't see why," she says, "they can't make them beautiful, the way they do jets and spaceships, out of graphite or epoxy."

She displays an admirable equanimity in the face of the jangling telephone and benign, last-minute chaos that any such festival engenders.

She was not so sure she would take the job with the National Committee when they first came to her several years ago and asked her to help."I thought, 'I'm being used, I'm a Wyeth and I'm on crutches.'"

But she had worked with disturbed children for a number of years and had been moved by the mysterious ways in which the beautiful could touch children whom no clinical understanding had been able to touch. They Played triangles, were charmed by rhythm, and learned how to count. One boy made beautiful vases, "and you could see immediately how brilliant he has."

So she helped to get the committee's appropriation doubled in Congress to $1 million, lobbying and making last-minute visits to senators to guard its passage. She helped with the festival-her husband and Andy Warhol will participate in one of the weekend workshops, each drawing the other as they did several years ago when they painted formal portraits of one another. (KEY OFF) art (KEYWORD) of the purpose of the festival is to show the ways in which the arts can help the handicapped to learn-and to change a few attitudes as well. Phyllis Wyeth herself has had more than a little experience with the ways in which people forget how impolite pity can be.

"You see it in their eyes, they have 'poor darling' written all over them. Some times people stop you on the streets to pray for you." When she was single, the men she would meet would "tell you how they wanted to take you out to talk to you," as if sexuality had been blotted out on the hills of a Virginia highway one October afternoon.

It hadn't. She met Jamie Wyeth at a New Year's party she had reluctantly attended. She liked him, "He was so natural." The idea of marriage came as something of a surprise. "I figured I would always be a career girl," she said. "No one was ever going to take care of me."

When they'd decided to marry, she said it was only to be for a year at first. "I didn't want him to feel that he had me strung around his neck."

That was 10 years ago. She looks startled for a minute that, indeed, a decade has passed. Her time is spent with him on their farm in Pennsylvania, among the rocky glories of Monhegan Island, Maine, and in Washington working with the Committee which is involved in aiding similar festivals, research projects and programs.

The past is remembered vividly, and recalled, upon request, without false humility or bravado: the dizzying pain of sitting up the first time, the 10 percent chance of ever standing again, the hours it took to walk across a room in the beginning.

"I said to myself, "All right Phyllis what are you good at, what do you like?'" The answer, she says, is much the same as it might have been without the accident. "I'd always wanted to work with people, particularly with disadvantaged youth. People said after the accident, 'Phyllis you've changed,' but I don't think I did."

And no, she has never had "a bitter day. Not one. I figure everybody's got problems. You've probably got some of your own."

There is one question that Phyllis Wyeth, who tears around her own farm in a hand-controlled Volkswagen, has had to put up with simply because of a rather famous painting her father-in-law did some 30 years ago, "Christina's World" shows a crippled farm girl looking past an eternity of tall grass to a farm house in the distance and the picture says much about limitations and cramped lives.

"It gets asked a lot," she says. "I just laugh and say, 'I'm no Christina.'" CAPTION: Picture, Phyllis Wyeth, by Joe Heiberger-The Washington Post