NOW THAT THE last words of the pilot and copilot of Air Florida's Flight 90 have been transcribed for everyone to read, the easiest thing for the aviation establishment to do will be to blame those 78 deaths on the actions of foolish men and drop the matter.

It's neat that way and it makes everybody feel better because it is a simple explanation: The pilot did it.

That explanation, however, is too simple, even though both the National Transportation Safety Board and the Federal Aviation Administration will be under substantial pressure to accept it.

While some will argue (with the benefit of hindsight) that the crew of Flight 90 should not have taken off in the first place, one can assume that Capt. Larry Wheaton and copilot Roger Alan Pettit did not set out to commit suiide. If you accept that proposition, then the question of why they took off, considering the weather, has to be addressed.

The FAA and its parent Department of Transportation have an institutional interest in accepting the simple answer, because it makes it easier to avoid a lot of unpleasant questions:

Why do we let people fly in blinding snowstorms anyway?

Should we really leave the final decision on whether to take off to the pilot who must, after all, be ultimately responsible for the safety of himself and his passengers? If we're going to interfere with that hoary tradition, who should make the decision?

Are the air traffic controllers providing the best possible information about weather and runway conditions?

Isn't the main runway at National Airport (which -- to add to the institutional interest -- the FAA owns, plows and sands during snowstorms) too short for aborting a takeoff in a snowstorm?

Remember the transcript. Wheaton and Pettit talk a lot about ice and snow, but the first time they mention slush is just before takeoff, when they obviously saw slush on the runway. Slush is known to substantially slow down jet airplane acceleration, but the pilots had not been told about it in the weather information they received.

At the same time, Wheaton and Pettit are bouncing along in the line of airplanes, watching 15 others take off. While there is a lot of talk about ice and snow and the value of de-icing trucks, nobody else is pulling out of that line to go back and get de-iced, as, it has been suggested, Wheaton and Pettit should have done. The tower is pushing flights out of National as if it were a nice clear day. Despite all the jocularity, Wheaton and Pettit ran through their checklist correctly, according to aviation experts.

If nobody else if having problems, why should we have problems? We're more than two hours late and it's warm in Tampa. This is a powerful machine. Even with one of its two engines out, it is supposed to be able to climb safely off the airport after it has reached go-no-go speed, so there certainly shouldn't be any problem with the snow.

How many times have you survived doing something stupid in an automobile that you knew, deep down inside, was stupid?

The most chilling part of the cockpit transcript comes after the airplane is rolling. Put yourself in Wheaton's and Pettit's seats.

Once the plane starts down the runway, Wheaton and Pettit clearly become worried. They're gaining speed rapidly, and something is wrong. "God look at that thing!" What are they looking at? An engine-performance gauge? "That don't seem right, does it?" What don't seem right?

Why didn't they stop, right then? Well, if you're sailing along a snow-covered runway at 100 miles an hour, what happens if you brake? If you know the runway ends, for all practical purposes, in the river, what are your options? Pilots know what happens to braking action on snow-covered runways -- even long ones -- and so do the rest of us after looking at those pictures from Boston of that World Airways DC10. The questions don't end there.

There is still much work to be done on the performance of the engines, and the question of whether they were delivering the right amount of power remains unanswered. Safety board experts are tearing them down to find out.

Air Florida is one of those little airlines that has grown enormously because of aviation deregulation. It has brought us a wonderful price war on tickets to the sunshine, and everyone has benefited.

But in the few short years that Air Florida has changed from a small intrastate carrier to a major force on the East Coast's most profitable wintertime runs, it has had to hire and train pilots quickly, acquire airplanes, arrange maintenance, etc.

There is no suggestion this hasn't been done professionally and with care. However, at the time Air Florida (and other burgeoning airlines) are gearing up, the federal safety regulator, the FAA, has been stretched a little thin. That stretching is continuing in the new budgets, and there is a regulatory climate in the new administration that says business is its own best overseer. Is it?

These questions are still there. If they go unaddressed, if everyone smugly assumes that Wheaton and Pettit are solely responsible for part of Washington's terrible Jan. 13, then the aviation community will have missed an opportunity to make a major step forward in safety.