The final public hearing on the future of National Airport was held last week amid charges that plans by the Federal Aviation Administration would do little to ease the noise and air pollution generated by the 1,000 planes that use National each day.

The heavy traffic at National, described as one of the nation's busiest airports, was criticized by several citizens as dangerous. One said there is "an atmosphere for a major disaster" at the airport.

Alexandria Mayor Charles E. Beatley Jr., a retired United Airlines pilot who handled flights from National and Dulles International Airport, told the hearing that National is not as safe as Dulles and criticized FAA plans to allow National to serve more passengers.

More than 15 million passengers used National last year, and the FAA has proposed allowing 18 million come about by allowing wide-bodied jumbo jets at National. According to several reports, the wide-bodied planes are quieter and can handle about 300 passengers, twice the number carried by the two- and three-engine jets now permitted at National.

Bentley criticized both proposals, noting that National is a short "one-runway airport . . . designed in 1941 for DC3s. And nothing's changed. The runway's the same, the hangers and the roads," National's main runway is 6,780 feet long, compared to the twin 11,000-foot runways at Dulles.

And, Beatley added, although Dulles was built to replace National as Washington's major airport, "you're proposing to increase use of National by almost the total amount of traffic at Dulles now."

He said Alexandria residents suffer most from the noise at National, according to the Faa's own noise monitors, and urged the FAA to cut off growth at National and encourage it at Dulles.

Robert B. Ryan, the citizen who referred to "an atmosphere for a major disaster at National," said he was speaking for 800 families who live in Harbor Square, a Southwest Washington apartment and townhouse complex "1.5 miles due east of National." He criticized the FAA for allowing heavy air traffic at the airport and called for an end to the "hazzardous" sharp right turns over Harbor Square that many jets taking off to the north now use.

The majority of the 100 speakers at the three hearings were Washington-area citizens, civic group representatives and elected officials strongly opposed to most of the FAA plans for National and Dulles. Under the plans, National would remain Washington's main airport beyond the year 2000.

The FAA will consider written comments on its proposals if received before April 15. It is expected to announce a decision this August and any policy changes at National will go into effect Jan. 1.

Some FAA proposals to reduce noise -- such as limiting evening flights and shutting down National after 10:30 p.m. -- won strong support from local speakers, but brought opposition from airlines, pilots and owners of private and business planes.

Sen. John Glenn (D-Ohio), the first U.S. astronaut to orbit the earth, said he commutes to Ohio in his two-engine plane and urged the FAA hearing to continue to allow private planes to land at National at night because they make little noise. "I often come in at midnight or 1 a.m., but I come in at idle speed. It's almost impossible to hear from inside a house, even with the radio or TV turned off."

The Air Transport Association of America, representing the 13 major airlines that use National, and the Aircraft Owners and Pilots Association, representing about 70 percent of the nation's business and pleasure aircraft, also opposed further night restrictions.

Representatives from Houston Birmingham and Norfolk protested two FAA "perimeter" proposals that would continue the ban on nonstop flights to cities more than 650 miles from Washington or would increase the perimeter of nonstop flights to 1,000 miles.

At present, seven cities are exempt from the 650-mile limitation, under a "grandfather" clause that was part of the 1966 order that first permitted jets at National. That order was designed to keep National as the capital's short-haul airport and to encourage use of newly built dulles as a long-haul national and international airport.

Robert E. Cohn, of Houston, called the distance limitation "Arbitrary . . . nonsense. National isn't a short-haul airport. It serves the same cities as Dulles and BWL, and in many cases has more flights to those cities . . . (such as) Los Angeles, Portland, Las Vegas."

To meet the 650-mile rule, Cohn said, many flights now stop at small cities "and the policy just encourages a multistop service, requiring more take-offs and landings."

Houston is just over 1,000 miles from Washington and would not be included in either proposals being considered by the FAA. Birmingham is 800 miles away. Norfolk's spokesman said his city, which would be exempt from either proposal, came to the hearing simply to oppose "existing restrictions and any further restrictions."