There will be a bigger, more modern control tower at National Airport in a few months, one that will give controllers more elbow room and a better view of the planes they guide in and out of the 14th busiest airfield in the United States.

An old tower, completed in 1949, could not meet the demands of the '80s, a Federal Aviation Administration spokesman said, adding that it had "reached the point where it was crowded. It had been there a long time. It was antiquated and archaic."

A temporary tower was built in 1982 and the old one dismantled, clearing the way for construction of the new glass "house" on the same spot atop the main terminal building. Construction started in January 1983 and should be complete by August, the FAA spokesman said.

Developments in aviation had outpaced the old structure, the spokesman said. While it was in use, he said, "we went . . . from propeller airplanes to jets. Washington National became one of the busiest airports in the entire country, and we were still existing with a tower that was archaic at best."

National served 14.8 million passengers in the 12 months that ended in January, and there were 337,977 flights (takeoffs and landings) during that period.

The new tower will have an area of about 600 square feet, compared to the 400 square feet of the old one. Its construction -- plus related changes including wiring, dismantling the old tower, transferring equipment to the temporary one and renovating the room below the tower where controllers monitor radar screens -- will cost $7 million.