MAYBE IT IS just as well that Secretary of Transportation Drew Lewis has suspended until next fall the proposed rules cutting back the commercial airline flights at National Airport. This community can endure one more spring and summer of misery if that is what it takes for Mr. Lewis and his staff to understand the anguish this airport inflicts and to build up the courage to do something about it.

Before Mr. Lewis and his colleagues can fully appreciate the magnitude of the decision they have postponed, they will have to do some personal factfinding in addition to reading all the relevant documents and listening to all those who want to be heard. They should, for example, spend a few early morning or late afternoon hours trying to conduct quiet conversations in home or apartments in Foggy Bottom, Georgetown, Alexandria and Arlington. They should visit National Airport on a Sunday evening and try to plow through the terminals to ticket counters and flight gates. Above all, they should have lunch on almost any day at Dulles Airport so they can enjoy not only a trip along the world's longest private driveway but also the solitude that fills this almost vacant monument to a well-conceived but never executed plan.

Once those things have been done, Mr. Lewis and his staff will be better able to compare notes with members of Congress, whose love for National's convenience does not diminish, and with thousands of citizens who pay the price every day for the easy access those congressmen enjoy.

After all that is done, Mr. Lewis will need to reflect on some basic questions. Should the federal government be operating commercial airports, particularly now that one of them is competing directly with a state-operated airport? If this is an appropriate exercise of federal power, should the government continue to ignore that competition, let Baltimore-Washington International outpromote and outperform Dulles, and accept a perpetual deficit on its costly investment in Loudoun Country?

Mr. Lewis will also need to ponder how the federal government can justify the inherent conflicts of interest that exist when one agency is charged with ensuring the safety of airplane travel and also with operating two airports and promoting aviation in general.

We won't suggest just now the conclusions Mr. Lewis should reach after gathering all the evidence and thinking about these questions. Regular readers of these columns already know our views.

But we do suggest that Mr. Lewis recognize the importance of the decisions he must make to this community's tranquility and economic future. That is the least he can do for having denied it this spring the minimal steps toward a rational airport policy that his predecessor was prepared to take.