The flight, an American Airlines charter, left Dulles yesterday at 10:40 a.m. Only the weather was sullen. Abroad the specially outfitted 707 (filet mignon dinners, rivers of booze and a movie that practically nobody watched) were 126 leather-lunged humans. Some were Capital Centre employes and the rest were your average, rabid, Washington sports fanatics - each of whom had paid $350 and abandoned work to go across the continent for 24 hours and cheer the Bullets for 48 playing minutes.

Carl Grogan,32 , manager of a safe-way in Rockville, a father and husband who is not know for taking leave of his senses, was one. He had found out about the charter at 5:45 the afternoon before. His mother-in-law had heard an ad on the radio and had phoned him at the store. He about threw down his apron and walked out the door, he said, still sounding unable to believe it.

"I decided I'd sell Safeway stock, charge the trip, anything - I just had to go," said Grogan. "I'm really psyched." He italicezes the "really," arching his brows, as if he were slightly daft. "I told the girls at the checkout counter to look for me on TV."

Actually, Grogan had a special reason for his Bulletmania - he is a friend of Elvin Hayes. Hayes shopped in the Columbia, Xd., Safeway that Grogan once managed. "E" has been over to his house four times for dinner already, Grogan said. "I want him to know he's got my support - at any cost. It'll be worth it - even if they lose."

"Grogan said he always waited for his hero-friend by the press gate after Capital Centre games. Following Sunday's win that tied the championship series at 3-3, Grogan got seveal Bullets' autographs on the back of an old T-shirt he had silkscreened with a giant E.

"I got home and my wife Peggy said, -Well, I guess you can't wash it now,' and I said, 'Yeah, Pet, I guess we'll have to start sending it to the dry cleaners.'" The Ecumenical Spirit

A few rows down, benignly smiling, hands folded across his black clerical suit, sat Msgr. Vincent J. Mackey, pastor of St. Cecilia's Catholic Church on Boston's Back Bay. (Fenway Park is in the parish.) Mackey, too, is a rabid Bullests' fan, but his route is a little more circuitous.

He is a friend of caach Dick Motta, having met him years ago through XEL football coach Hank Stram, then of the Kansas City Chiefs. It was nothing back then, said the priest, for him to say his two Sunday masses at St. Cecilia's, then hop on a TWa flight to Kansas City to catch the tail end of a late afternoon NFL game. That's how he met Motta.

Now he and Motta are fast friends. Some, in fact, have suggested the pafre was Motta's pipeline to heaven: Every time Mackey came down to Washington for a game this year, the Bullest won. A couple of weeks ago team owner Abe Pollon got wind of the coincidences and reportedly said: "Get him down here again. And if we make it to Seattle for the finals, get him out there too."

"Funny," said Mackey. "Motta's a Mormon. Pollin's a Jew. And I'm a priest."

Mackey, who ran varsity track for Boston College and recently celebrated his 40th anniversary as a priest, was worried about getting to a Seattel for the finals. He conducted a novena to Our Lady of the Miraculous Medal every Ruesday night on Boston radio stations, and he hasn't missed in 30 years. But the charter yesterday morning solved everything, thank the Lord. All Charged Up

Joe Zamoiski is in electronics. He owns a distributorship in Washington and Baltimore that employs 300 people . But sports, especially the Bullets, have been coming first lately. Zamoiski has been a season ticket holder since the Bullets moved to Washington, he said. This year's team has lit his fire.

"Let me put it to you this way: I'm a great civi c booster, so naturally I think the Bullets are good for Washington.But on a personal level, these guys seem to speak to me directly. I don't know... you sit right behind the bench, you see them sweat, get angry and you can't help getting involved. Hell, my wife is as bad as I am. She's been in a leg cast this year, and do you think that stopped her? She rode up the elevators at the Capital Centre."

Zamoiski, a short, animated man, stopped cold. He leaned close, as if to share a secret.

"I've been going to Washington pro sports events since 1946, when I moved here from Baltimore. I've never seen a Washington team take it all. I thought the Redskins were going to do it at the Super Bowl a couple of years ago, but they let us down. This team isn't going to break my heart, I know it."

Stand Up and Cheer

Someone else on the charter, who seemed about as different from Zamoiski as one could imagine, echoed similar sentiments. Bruce Benjami, 25, is a partially rehabilitated victim of a head-on auto collision. That was three years ago, and at the time the doctors wondered if he would live. He was in a coma for 2 1/2 weeks. Since last September he has worked for the Bullets management helping keeps stats and occasionally throwing the ball around with the players in practice.

Benjamin, in sneaks and blue jeans, looked out the window during mid flight. "I can't believe I'm going back to Seattle," he said, "I was just there last week." Then he added, "Without sounding trite, the Bullets have giben me something to live for. I've come with them this far. There's no way they can lose." Sonic THud

The plane set down at the Seattle airport about 3:45 p.m. Washington time after a five-hour flight. By then you could have sliced the air in the cabin with a butter knife. The captain came on a few minutes earlier to ssy the control tower had told him to divert to San Francisco because of some weird sonic booms, but no one was ready to believe this. Mike Riordan, retired Bullet, and Phil Chenier, disabled Bullet, didn't even bother to look up from the pinochle game they were playing on the aisle floor.

And a chubby little girl who said her name was Marcey and who was carrying a scribbled sign that said, "Silence the Sonics," announced to everyone within earshot: "We beat whoever is in San Francisco, too."

Within an hour of arrival in Seattle, the sun came out, and Puget Sound sparkled blue.