Gerard T. McDonough, the garrulous chairman of the Prince George's County Council, blew smoke from his cigarette in satisfaction. At 35, he is secure (a third term this November seems assured) in a job he loves, in a place that, for a child of the hard-scrabble coal country around Scranton, Pa., represents "the good life."

Gazing out the picture window at the lush, undulating fairway of the modest Marlboro Country Club, he recalled that he got into politics for the best possible reasons: He needed a job and he knew someone who could get one for him.

It was 1972 and McDonough was fresh out of the Marines, hoping to land a job with a defense contractor or, because of his flying experience, with a commercial airline. But the fuel crunch was beginning to hit the airlines and McDonough was running out of his savings. So he turned to the one politician he knew--his 22-year-old brother John--who told him of a possible opening at the county office building.

The aide to then-Council Chairman John Gerrity had just quit, so McDonough drove to Upper Marlboro for the interview. The job was his--the kid brother had paved the way--but the pay wasn't all that great. "It was $8,773 a year," recalled McDonough. "I'll never forget that, because I had just left a job in the Marines, as a captain, that paid $12,500."

But a job is a job, so he took it, and after two years of learning the ropes, McDonough, a gregarious guy to whom glad-handing comes naturally, ran for council in 1974. With the help of Winfield Kelly's Democratic political machine, to which he attached himself, he won easily. Four years later he was reelected, and this year he may not even have an opponent.

McDonough is at the county office building four days a week, but on most Fridays, he squeezes into a silver flight suit ("If I had a 32-inch waist and no jowl, I'd be hell," he laughed) and heads for Andrews Air Force Base, one of the county's landmarks. At Andrews, Marine Reserve Major McDonough works on an F-4N, as a Navy flight officer or the GIB ("guy in the back" in Navy jargon). On training missions, he directs the pilot into position for firing one of the fighter jet's eight radar-guided Sparrow or heat-seeking Sidewinder missiles.

It's partly a love of flying that attracts McDonough to Andrews once a week (as an active reserve, he is required to practice only once a month), but it's also a matter of money. His county paycheck has increased almost four-fold since that first year--as council chairman he makes $30,317--but he says it's still not quite enough to pay the bills at his town house in the Largo subdivision of Prince Place II ("Isn't that obnoxious," he moaned), where he lives with his son Jerry, 13, and daughter Erin, 8 (McDonough is divorced).

The lack of serious opposition may make it easier for McDonough to oppose, after lukewarm support, the TRIM amendment that places a cap on county tax revenues. He believes the county government has managed to function without serious repercussions to basic services. "But this year," he said, "it's evident we're running out of room." Republican County Executive Lawrence J. Hogan's proposed budget, at the TRIM limit, is $8 million shy of what McDonough says is needed to fund legally binding agreements with county employes, primarily with its school teachers.

One solution being touted by the Parent-Teacher Associations and public employe organizations is called Plus 4, a referendum item that would permit a 4 percent annual increase in the TRIM limit. McDonough may endorse Plus 4 after the council completes work on the budget, but he sees any plan that works with the existing tax formulas as temporary.

"The issue is tax reform," McDonough believes. "We have to find a means of moving local government away from dependence on property tax as a primary revenue source." The problem won't be solved, he said, until local revenues are tied to ability to pay, which means county income or sales taxes.

Despite limited taxes, a new lawsuit by the NAACP charging that the schools are still segregated and pressures resulting from federal budget cuts, McDonough isn't defensive about his home base. The quality of life in the sprawling county--it's nearly half the area of Rhode Island--is rich and diverse, from the natural beauty of its rolling hills and streams and tobacco farms, to man-made attractions such as the Capital Centre, University of Maryland and, of importance to McDonough, Andrews Air Force Base.

"I don't chafe under the occasional reference to us as an ugly sister, because I know we're not. Our amenities are the equal of any in the area," he said, glancing at the ninth green, where four young men, two whites and two blacks, were putting. "No other jurisdiction in the Washington area is meeting the challenges we are of a mix of people trying to live together, and handling it."

Marlboro Country Club is, like the county in which it is located, McDonough's kind of place. "I know it's not Chevy Chase," he said, "but then, I'm not a Chevy Chase kind of guy. I wouldn't be comfortable there, and neither would my friends."