By now, we all know the thrilling background Howard Cosell boarded an airplane in Los Angeles, where he was broadcasting the World Series. A Philadelphia sport columnist, Stan Hockman, said something sarcastic. They exchanged a few more remarks. Then Cosell slapped Hochman's head a few times.

The columnist indignantly says his head now hurts, and nobody can slap him and get away with it, and he is going to sue.

It isn't easy for me to side with Howard Cosell against a fellow columnist. Like most decent, patriotic, God-fearing Americans, I consider Cosell a menace to my sports-viewing pleasure, which is our most precious heritage.

But I also believe in certain basic rules of fairness. And one of them is that if you choose to say something nasty to someone, and he tries to pop you one, you either pop him back, run, or talk him out of it.

The columnist says he is going to sue because, "Nobody . . . has the right to smack someone in the head and walk away."

I agree. As he walks away, you hit him with a chair.

Beyond that, there are extenuating circumstances because this case involves Howard Cosell.

Nobody in my memory has been written about as unflatteringly and by as many sports columnists as has Howard Cosell. He may deserve it, but at this point he is probably tired of it. I know that I'm tired of reading it.

But what can he do to fight back? He can't very well go on baseball or football broadcast and babble about all the hundreds of thousands of sports columnists he hates, and describe what disgusting creatures some of them might be, how this one doesn't change his underwear regularly, and that one can't spell, and another one wears an even cheaper hairpiece than Cosell does.

If he tried to anser all of them that way, he'd have to be on the air for a week, which would cause mass rioting in American cities. And on farms, too. (ROYKO, From G1>

He can't sue, either, because most of the terrible things they say about him are true, and truth is a solid defense. It is one thing if a sportswriter says Cosell is a stiff. But if a legal decision declared him to be a stiff, that could be very depressing for Cosell.

So that leaves him with two options: Accept the criticism or punch the critics.

Cosell is no dummy. He is not your basic frightening physical speciman. So he can't go around punching all of his critics, although if he tries it would make a wonderfully funny segment on "Wide World of Sports."

But as disgusting as he is, he is also human. And even a disgusting human doesn't want to be reminded all the time that he is disgusting.

So in this one instance, he struck back. Or at least slapped back. And I'll say this for Cosell. He knows when to pick his shots. Hochmans, who is 49 and 5-foot-9, was sitting on the airplane with his safety belt buckled when he made his sarcastic remark to Cosell, who was walking by.

And if you are going to give anyone a few slaps, there's no better moment than when he is strapped into a chair and you aren't.

On the other hand, if you are going to say something sarcastic to anyone, there is no dumber time to do it than when you are strapped into a chair and he isn't.

The safety belt, the columnist says, is why he could not defend himself and slap Howard back.

Well, who's fault is that If you're foolish enough to lip off to someone while you're strapped in a chair, you deserve to have a ringing in your ears.

As Slats Grobnik said: "If you can't say sump'n nice about someone, then make sure that when you say sump'n bad you are in position to kick him inna groan."

This is the type of thing that should have been settled man to man, or if that wasn't possible, sportscaster to sports columnist.

Since Cosell was on the same plane, there was ample time and opportunity for the sports columnist to have unsnapped the seat belt, sought out Cosell, and leaped upon him like a raging beast, tearing him limb from limb, or eye-bag from eye-bag. No jury of sports fans would have ever convicted him.

If he din't feel up to that, he could have waited until Cosell had put on his safety belt, and then tweaked Cosell's nose.

Or he could have plucked Cosell's hairpiece from his head and turned it over to the pilot as a suspicious creature. Whatever he did would be better than bringing this whole sordid [WORD ILLEGIBLE] good can come of its except a giggling fit by the judge's bailiff.

And, a final word of caution if he intends to sue for damages. Some of my best friends are sports columnists. But most of them would have a hard time convincing a judge or jury that a blow to the head could effect their work.