THE TRANSITION is sure to be a nightmare, but this is the Year of the Grand Departure at National Airport -- when the regional authority starts turning this terminal into a modern, efficient and -- if all goes according to plan -- approachable place. The idea is to get rid of most of those old sad shacks and the hodgepodge of narrow roads, allowing room to erect a three-story building with a double-decked roadway for departures and arrivals -- along with a direct connection to the Metro trains.

This does mean that veteran travelers will in time be separated from some of National's least attractive features, including: the great circle route to every jammed parking lot; the beast-of-burden trek across the great divide of traffic that now separates Metro from everything else and the musical chairs in the sparse-seat waiting rooms.

Don't laugh, but the current main terminal actually is registered as a historic structure -- and it is to be restored for reduced use by passengers. The 33 aircraft gates there now would be reduced to 12, and 10 gates would be reassigned to smaller commuter aircraft. The new terminal would have gates for 32 jets.

There are opponents, most of whom have consistently opposed any serious improvements of National on grounds that its use should be reduced if not ended, that fixing up will only increase the noise levels. Airport and airline officials insist that the improvements will not affect noise, that newer and larger aircraft are quieter than many planes now in use. All this remains to be seen -- and, if true, dealt with. But the fact is, National is an important airport that is here to stay and should be brought into the modern world.