The man who forced the grounding of America's DC-10s last June is a suave, 49-year-old former insurance company troubleshooter who says he may spend his company's entire 1979 profits - about $200,000 - to keep what he thinks is an unsafe jet out of the air. He's James E. Dunne, president of the 55,500-member Airline Passengers Association, Inc., a profit-making company that hitherto was known mainly for the travel insurance and lost-bag-locating service offered members.

"I wouldn't fly on a DC-10 today," says Dunne, who doesn't think the more stringent safety and inspection regulations ordered last month by the government and the aircraft's builder, McDonnell Douglas, have made the plane airworthy. Operating from a $175-a-day suite at the Madison hotel, Dunne watched the FAA wrestle with the aftermath of the June crash near Chicago that killed 273 people. His decision to seek a federal court order to ground the DC-10 helped put the plane temporarily out of service.

As well as going to court, Dunne retained an aviation engineer and testified before Congress. Why the sudden zeal on the part of a man whose last brush with the courts was when he filed for personal bankruptcy in 1970? That was when a fast-food franchise - Mickey Mantle's Country Cookin" - broke his bank account.

Dunne says his conscience - not his desire to attract new members - made him do it. He talks of the honor of his father and grandfather, who ran a prosperous printing and publishing company in Louisville, Ky. He speaks of his years in the insurance industry as a consultant to companies in financial trouble, his bankruptcy and subsequent successful effort to repay all his creditors, a nervous breakdown, a heart attack...a personal litany he says culminated in a decision to place the APA on the front lines of the DC-10 battle.

"We always sort of knew the APA existed down in Dallas, but they hadn't been terribly active," says Con Hitchcock, who works for Ralph Nader's Aviation Consumer Action Council and says he hopes the APA's activism will continue.

Dunne says the APA has had a rocky history since its founding in 1960. For some time it operated at a loss, though several insurance firms tried to use it as a vehicle to sell travel policies. When Dunne bought the company eight years ago, it had 14,000 members. He paid $75,000 and assumed a $313,000 bank note.

"Jimmie," Dunne remembers a banker friend saying to him at the time of purchase, "I admire your beliefs, but you've made a terrible mistake."

Dunne says the APA paid off the bank loan and moved into the black two years ago. After a heart attack about that time, he decided to assume an advisory role in the company, and until the DC-10 issue, he was making progress toward moving his 35-year-old third wife and 3-year-old daughter to Tortola in the British Virgin Islands. That's still in the cards, but Dunne vows Washington hasn't heard the last of the APA.

He wants to reduce the airline ticket tax and force the government to spend more quickly the funds it collects to upgrade the safety of airports. "The thing that emerged from the DC-10," he says, "is that we should have been here before this." CAPTION: Picture, no caption, By Bill Snead