Fonda in a Clarifying Mood. Amid a host of career successes, she still feels a need to explain her '72 trip to Hanoi. ACTRESS: ACTIVIST

WITH black sweater, black pants, black boots, and still that head-turning smile, Jane Fonda is talking about the ``passages'' of her life - about coping, changing, growing, and surviving. Her office suite is adorned with the trappings of fame - Oscars and photos of herself as a Hollywood child, an actress/producer, and an exercise maven - which suggest she has done more coping than most.

Now at 51, at least one public opinion poll gives her a higher popularity rating than President Reagan.

In an interview here at Fonda Films she has no air of self-importance. She is interested in her interviewer as a father (``Your wife works, and you have a child? How do you cope?'') and her photographer as a Vietnam veteran (``1972 - so you were there after the Tet offensive?'').

Later, she will talk about the women's movement, role models, activism, family life, acting, and producing. But first, she faces the obligatory question about her conciliatory statements about Vietnam on the ABC-TV show ``20/20'' last year.

Interviewed by Barbara Walters in July, Fonda talked about her 1972 trip to Hanoi, when she climbed onto a North Vietnamese anti-aircraft gun to pose for photographs, and made a propaganda broadcast to US servicemen stationed in the Gulf of Tonkin.

``I would like to say something ... to men who were in Vietnam, whom I hurt, or whose pain I caused to deepen because of things that I said or did,'' Fonda told Walters. ``...I feel that I owe them an apology.''

After all these years, Fonda still felt she was a lightning rod for frustration about the war. The Walters interview came at Fonda's request.

Today, here in Santa Monica, Fonda wishes to clarify a general misimpression held by many who did not watch the whole telecast, that she was reneging on her antiwar involvement.

``I did not, have not, and will not say that going to North Vietnam was a mistake,'' she says. ``I have apologized only for some of the things that I did there, but I am proud that I went.''

Posing on the anti-aircraft gun was wrong (``thoughtless and careless''), she says; publicly criticizing certain POWs she felt were used to glorify the war was wrong. But traveling to Hanoi to bring attention to secret bombings of dikes in North Vietnam was not wrong, she adds.

``I feel I tried to end the war, and in some small way my actions helped end the war,'' she says. ``I know not everyone agrees ..., but I also got hundreds of letters from vets [after the Walters interview] that said, `I'm disappointed that you felt you had to apologize. I hope that you are not backing down.'''

No one has been more amazed than Fonda that the whole controversy still brews. Last summer while she was in Waterbury, Conn. to make a film, a veteran's group had sold 6,000 ``We're not Fond'a Hanoi Jane,'' bumper stickers and promised demonstrations that would rival the Tet offensive.

Fonda, however, reversed a hostile situation after a four-hour meeting in the basement of a local church.

``They had their anti-Jane Fonda stickers and all the hate stuff all over them, and I told them what I was sorry for and what I wasn't,'' she says. The clarifications defused anger, she said, but she says she learned ``two horrible things:

``They really believe ... that, had it not been for the antiwar movement, we would've gone on to a military victory. And they believe they are the first American soldiers to lose a war for the US.

``I said, don't you understand that the men who sent you knew that the war could not be won? [Former Defense Secretary Robert] McNamara has admitted knowing in 1965 that the war could not be won.

``They couldn't hear me. For them, it was their fault.''

FONDA has continued in the spotlight, with the making of two recent movies and a third generation of million-seller exercise videos. Too busy to be a full-time activist, she still uses her celebrity to spotlight issues close to home and heart: various California initiatives (1988), the Solidarity movement in Poland (1987), and the plight of Soviet Jewish refusenik Ida Nudel (1987).

Fonda is married to Tom Hayden, the California state assemblyman she calls her ``anchor'' and someone ``without whom I don't know what I'd do.'' They live here in Santa Monica with their teen-age son, Troy, and their daughter, Vanessa, when she is home on breaks from Brown University.

Despite all her activity, Fonda takes the initiative to disabuse inquirers of any notions about superwomanhood.

``I'll tell you who the superwomen are, in my opinion,'' she says. ``Those who raise a family, hold two jobs, and put themselves through college.''

If Fonda has any niche in the women's movement, it is in highlighting pay inequities and sexual harassment in the workplace - underlined by her movie ``Nine to Five.''

Owning up to having her own housekeeper, partners in film production and exercise videodom, and ``a woman who schedules my entire life to make it run smoothly,'' Jane Fonda says she feels it's important for her to keep her feet on the ground.

`THE big problem for someone who is wealthy and famous and privileged is that they get too much on their high horse, get very separated from reality into some rarefied atmosphere [where] they are never forced to look at their own behavior. It frightens me very much.''

That she has gotten her feet firmly planted is evident in the conviction and ease with which she spins out folk wisdom about the various facets of her career.

On activism: ``Patience. The big lesson is that things don't happen quickly. You know, when you are younger you think, `Well, if I speak out and expose a fact, people will hear it and change, and things will get better.' But I see more and more, everyday, that change is frightening for people. The most recent elections show the status quo is comfortable for people.''

Aligning with causes: ``Choose the issue and initiatives that will truly shift the balance of power away from special-interest groups and tilt it toward communities, consumers, the disenfranchised. That's what I look for.'' California's Proposition 65 (a far-reaching toxic waste regulation initiative) and Proposition 103 (which lowered the state's car insurance rates) were two recent measures that Fonda supported, and that won on the November ballot.

Choosing movie productions: ``I'm really proud of the fact that most of the movies I've produced really have something to say. ... It's always been couched in a good yarn that's either wrapped up in sex and romance, like `Coming Home,' or humor, like `Nine to Five,' or drama, like `China Syndrome.' There's always been a story you could relate to, whether or not you got the message.''

She calls her new film, ``Old Gringo,'' due out next fall, a ``strange epic, romance, drama, that is unlike anything I've ever done or seen.''

Role models: ``I like being one. It keeps me on my toes. It's been helpful for women in particular to have lived through with me my going out on a limb, my making mistakes, my surviving the mistakes, my admitting the mistakes and going on from there. I think, on a lot of levels, it's very helpful to people to show one doesn't have to give up. That you're not alone.''

Commitment: ``I'm disturbed by the number of young women who believe you can have a kid and raise it without a father. A normal marriage is best. Tom told me when we had Troy that one of us should be home every night until he went to college. He's traveled more than any state legislator to live up to that.''

BESIDES all the activities she is involved with, Fonda still cherishes her connection with the 13-year-old performing arts camp she established on her ranch in Santa Barbara.

Primarily for Californians, the enrollment is one-third inner-city youth on full scholarships, one-third on partial scholarships, and one-third privileged.

``The fact that this is everybody together - rich, poor, handicapped - makes it work. Everybody rises to the top,'' she says.

Fonda finishes the interview with a brief spot of wisdom on the importance of instilling values in children. ``You have got to live what you say, or they will trip you up as being hypocritical,'' she says.

Most of what is passed on to the younger generation is through osmosis, she continues. ``I saw the kinds of roles that were important to my father - in `Grapes of Wrath,' `Twelve Angry Men' - and it had a deep effect on me,'' she says.

Today, movies remain the strongest influence for her.

She recently took son Troy to ``Mississippi Burning.'' ``He knew Tom and I were going to Atlanta to march on Martin Luther King's birthday. And he said, `I want to go with you.'

``I'm so grateful that it affected my child so that he said, I want to be part of whatever will remind people that this can never happen again.''