This is the behind-the-cover-up story of why an Eastern Airlines jetliner carrying 175 people almost collided with a helicopter at Washington's National Airport on Sept. 24. The Eastern pilot had to abort his takeoff because the airport control tower was undermanned in favor of a golf outing.

Air control officials at National had permitted 20 air controllers to leave their jobs at 11 a.m. to play golf at the Enterprise Golf Course in Largo. Controllers who had worked the evening before were outraged when asked to come in early that Tuesday to "cover" for the golfers. Five controllers called in sick. A sixth controller was browbeaten into coming to work, but later left with a toothache.

So Fred Bolster, the supervisor in the control tower, was handling air traffic while trying to train a new controller at the time the Eastern jet requested clearance to take off. In his frenetic triple role, Bolster apparently never heard veteran air controller Pat Dew tell him that she had cleared the helicopter to take off. So Bolster sent the Eastern jet into what might have been the same tragic bit of air space.

The golfing controllers came off the Enterprise course about 5:30 p.m. to be told that TV was full of stories of a near disaster at National. Some controllers decided to rush back to the airport to make the tower numbers look good. Others said they didn't want to be within miles of that embarrassment and went home.

In the ensuing furor, some Federal Aviation Administration bureaucrats decided to make Dew the scapegoat, without ever revealing her name. The press simply was told that a woman controller had been transferred to other duties.

But other controllers at National say that Dew, whom I've never met or talked to, is one of the very best. The bureaucrats knew they couldn't get away with blaming her. So hours after the public was told that "a woman controller" had been taken out of the tower, Dew was recertified and back at work. She is probably in the National Airport tower as you read this.

Rep. James L. Oberstar (D-Minn.) tells me that the chief investigator of his investigations and oversight subcommittee of the House Public Works and Transportation Committee has confirmed every detail of what I have written above. Oberstar says he will hold hearings on this and other incidents.

Why do I come back to this story of apparent FAA lying, of bureaucratic arrogance, of playing games with the lives of Americans who must fly? Because the danger doesn't end with that near disaster of Sept. 24. The close scrapes recur, day after day, airport after airport, because our air control system is not staffed or organized to do a proper job.

On Wednesday afternoon, USAir Flight 312, bound from National to Louisville, was rolling toward takeoff when the pilot aborted, concerned about helicopter traffic in front of him. Harry Hubbard, chief of the control facility at National, says that the only helicopter traffic was "way up the river" and no danger to the USAir flight and that he has no idea why the pilot aborted that takeoff.

On Oct. 17 a Northwest Airlines jet, taking off for Detroit, was at 1,300 feet when a Cessna that had made a wrong turn flew under it. A Northwest official tells me that when the pilot got to Detroit he telephoned Hubbard and "blew his top." Hubbard confirms that the pilot called him, but says everything was okay once he assured the pilot that there was adequate "separation" between the Cessna and the Northwest aircraft.

Pilots, controllers and others in the industry tell me that these potentially tragic boners at National can be multiplied by the hundreds for the nation as a whole. They say that the skies will be unsafe until someone can get the FAA to admit it is not doing an adequate job, one reason being that it does not have enough skilled controllers -- on or off the golf course.