THANK heavens we're going to Washington, really going this time!" said Lucia Chase, smiling, all aflutter, looking incredibly girlish and trim. The appearance of the woman who has headed the American Ballet Theatre for 35 years and has just turned 73 bears powerful testimony to the magical restorative powers of the ballet life, whatever toll it may exact in other ways.

Seated on the edge of a couch in her small office at ABT headquarters across the street from Carnegie Hall, Chase was reliving the company's labor troubles this winter. "I was so embarrassed about the cancellation of our December season at Kennedy Center. The whole experience was pure agony, it nearly killed me. Every day I thought [the dancers and management] were going to sign, but it kept dragging on and on. And after all, we are the 'official' company of the Center -- have been since the place opened. This was disaster. Then when the contract finally was made, we had 23 days to prepare for a four-city tour -- it was a nigthmare, with a new ballet to get up, revivals of 'Billy the Kid,' 'Dark Elegies," and other things, and the company hadn't danced in 3 1/2 months. And on the tour, I never saw so many emergencies and injuries all at once. By San Francisco, though, we were even doing good business. Now we've got two weeks of rehearsal before Kennedy Center, the casting isn't set yet and my head's in a whirl -- but I'm praying we'll make a go of it." All this in one breath. Chase is not the only one looking forward to the ABT three-week engagement at the Kennedy Center, which begins Tuesday evening -- the first major ballet that's come this way since the New York City Ballet last fall. The troupe will arive here with a minimum of rehearsal, following an extended tour, and minus Cynthia Gregory and Gelsey Kirkland, ABT's two leading American ballerinas, who both resigned for different reasons. Company morale is rumored to be on the queasy side, given the approaching shift of artistic reins -- Chase will step down with co-director Oliver Smith in September, when Mikhail Baryshnikov takes over. He was already dismissed principal dancer Kirk Peterson, and there are rumbles of other changes in the making. The company, to use a peculiarly apt cliche, is at a turning point.

On the other hand, the visit will bring the washington stage debut of former Bolshoi luminary Alexander Godunov. In the first week, he'll dance on opening night in Balanchine's "Theme and Variations" partnering Martine van Hamel, and then on Thursday evening as Prince Siegfried in "Swan Lake," again with Van Hamel. Also on opening night is the Washington premiere of Daniel Levans' "Concert Waltzes." The season will include five notable revivals, as well as three popular full-evening ballets: "Swan Lake," "Giselle" and the Baryshnikov production of "Don Quixote." The repertoire will emphasize the mainstay choreographers who ensured ABT's glory in its early years -- Anges de Mille, Jerome Robbins, Antony Tudor and Eugene Loring.

The company will celebrate its 40th anniversary season here with a special gala program on April 9. Chase has ridden the waves with ABT for all four of those decades, and the name of her game has been crisis management -- in which she has demonstrated a special genius. She has rescued the company from financial ruin with her personal fortune on numberless occasions in the past. But she has also kept ABT afloat spiritually and artistically over the years with an instinctive tact and skill, and steered it to international eminence.

The beginnings are still vivid to her. Ballet Theatre, as it was then called, gave its first performance on Jan. 11, 1940, at New York's Center Theater. Chase danced in two of the three ballets presented, as the Prelude soloist in "Les Sylphides," and as A Little Girl in the innovative "balletplay" entitled "The Great American Goof," with a spoken script by William Saroyan, music by Henry Brant and choreography by Eugene Loring. The "experiment," though a flop, was indicative of the early adventurous nature of the troupe, and of its attempt to foster American creativity at a time when foreign names blanketed public awareness.

"I wore a short pink dress and a big yellow bow, and I came in saying, over and over again, 'I know everything, I know everything!" Chase recalls of "Goof." "We worked three months to put on that first program, and it was a glorious evening."

Chase had been reared in affuent surroundings in Waterbury, Conn. Her heart set on an acting career, she went to New York to study with Rouben Mamoulian at the Theatre Guild school, taking music and dance classes as well. Her principal ballet mentor was Mikhail Mordkin, a Russian dancer who'd left Diaghilev in 1909 and eventually settled in the United States to establish a company of his own -- the troupe that became the nucleus of the Ballet Theatre. Mordkin, whose other pupils included Hepburn and Judy Garland, lured Chase from drama toward dancing, teaching her major classical roles like Giselle and Aurora and casting her in leading parts. "He was a fascinating person, whose real gift was as an actor," Chase says. "Some said he was crazy, and you could see why -- he'd come in wearing striped pajamas, a black tie, high sneakers, singing and jumping all over the place. But when we formed Ballet Theatre, he was extremely upset when Dick Pleasant, who'd been his his business manager, handed the direction of 'Giselle' to Anton Dolin instead of himself. He left the company before our first performance, and never spoke to me again [Mordkin died in 1944], though years later his wife called."

Richard Pleasant, a Denver native who'd studied architecture at Princeton and then worked as an agent in Hollywood, where he became friends with many dancers, was the founding director of Ballet Theatre. "People say I founded the company," says Chase, "but I never dreamt of such a thing -- it was all Dick's idea. He used to get dancers movie jobs, but he was a true balletomane, he knew more about ballet than I'll ever know. He had this vision of making a really American ballet company on a scale with the great European troupes. 'American in spirit, international in scope,' he used to say, and that's what we've tried to follow ever since."

Under Pleasant, the fledgling company mixed classics like "Giselle" and "Swan Lake" (Act II) with contributions from such Diaghilev progeny as Fokine, Mordkin, Nijinsky and bolm, and introduced new work by such American tyros as Loring and Agnes de Mille. American dancers like Chase, Patricia Bowman, Karen Conrad, Nora Kaye, De Mille, Loring, William Dollar, Leon Danielian and Donald Saddler rubbed shoulders with such English and continental imports as Bolm, Dolin, Hugh Laing, Tudor, Andree Howard, Dmitri Romanoff and others. By the first summer, Jerome Robbins, John Kriza, and the Alonsos, Alicia and Fernando, were added to the roster. Quite a start. Another Pleasant conception was the original division of the troupe into "wings": an American wing, a classical wing, a Russian, an English, a Spanish and even a "Negro" wing, which, much in advance of its era, presented an all-black performance of De Mille's first major piece of choreography -- "Black Ritual (Obeah)" -- during the inaurural season.

Economic troubles led Pleasant to resign in 1941, and for the following five years, the company was under contract to Sol Hurok. There began a controversy over Russian domination of the troupe that rings a lot of contemporary chimes. "In the '40s," Chase recalls, "Hurok liked to advertise us as 'The Greatest in Russian Ballet, by Ballet Theatre,' and season after season the Russian Ballet got bigger and Ballet Theatre got smaller. We could see what was coming and we were getting real perturbed." Still, at the time Chase had no thought of running things. "I was completely happy as a dancer for those first five years," she says. But the power struggle was on and things heated up radidly in 1945. "I was probably known as a busybody anyway, so somebody suggested I take over -- for a year. I was dumbfounded and scared -- I certainly wouldn't do it alone, I told them. But that was when I had met Oliver [Smith, the designer, who had come to the company to do sets for the Robbins-Bernstein "Fancy Free" and other things]. It's 35 years later, and we're still here."

Chase and Smith became co-directors, and the liaison with Hurok was severed, not without ruffled feathers. Thereafter, the new leaders tried to follow the vision of Richard Pleasant -- to create a "living museum" of ballet art, joining the best of the new to the best of the old, remaining "American in spirt, international in scope." In 1957, following a precedent set on the company's international tours, the troupe was renamed American Ballet Theatre. Despite periods of triumph and renown, the sailing has rarely particularly during the long era of grueling cross-country treks that were the rule before the Lincoln Center, Kennedy Center, the National Endowment for the Arts and the recent public hospitality toward classical ballet introduced a measure of stability.

Throughout those years, Chase was never frustrated enough to quit. And even now, "I'm not leaving Ballet Theatre," she insists with a determined smile. "I'll still be on the board, and I'll even be able to keep my vice-presidency -- I think. I'll be around, I'll be working more with the board, and I'll do whatever I can to help out." Last year, Chase expressed to critic Walter Terry some doubt about whether Baryshnikov could continue performing and be an effective artistic director at the same time. Now she seems more reconciled. "I'm sure he'll come out all right," she says. "The company has such a good solid base, and he'll have that to work with. I shall certainly do anything Mischa might ask of me, though he's perfectly capable of taking care of himself, of course. The main thing is that the company keep on growing."