The Federal Aviation Administration, in an effort to keep order in the increasingly crowded skies around Dulles International Airport, has proposed that all pilots nearing the airport be required to remain in radio contact with its tower.

Currently, only those pilots planning to land at Dulles need to maintain radio contact. The proposed rules would mean that most airplanes flying below 4,000 feet within 10 miles of the airport would have to stay in touch with Dulles. The special zone would exempt some small planes flying at 1,000 feet or below.

FAA officials say creation of an Airport Radar Service Area would greatly enhance safety by giving air traffic controllers the full picture of planes in the area.

But an association that represents the owners of many of the country's 250,000 small aircraft says the new rules are meddlesome and would cause further confusion and delay without contributing to safe flying.

"We don't think the federal government has done its homework on this issue," said Edmund Pinto, senior vice president of the Aircraft Owners & Pilots Association and a former FAA official.

"The idea was to improve safety, but it will just constrict airspace and make it more difficult to fly. Our members don't think it's a good idea," Pinto said.

Pinto says that the radar service area would have the effect of forcing small aircraft to fly close to the ground -- below the level of mandatory communication -- and that it would therefore increase noise on the ground.

Supporters of the plan, which has been proposed at 66 airports in the country, say that it is necessary for safety around busy airports.

"This is the state of the art, a way to make flying safer," said Paul Leonard, a vice president of the Air Transport Association, which represents most of the country's major commercial airlines and has given strong support to the FAA proposal.

"This will help each controller identify every plane in his airspace. They will know that it's there and what altitude it is on. This helps eliminate unknown entities," Leonard said.

Air traffic controllers at Dulles say that they are behind the new program, and that any system that helps fill them in on what is flying in their area is welcome.

In traveling between airports, pilots of private planes are not normally subject to the strict guidance of the FAA's air traffic control system. They may rely on eyesight in good weather to avoid other aircraft.

Airlines operate under stricter rules, and their pilots must follow traffic instructions from controllers on the ground.

Normally, planes flying only by what pilots refer to as visual flight rules are not allowed in the heavily congested areas around most airports.

Over the years, the FAA has set aside increasing amounts of airspace near many airports where they have restricted flying and require guidance from the ground.

A radar service area has been established at Baltimore-Washington International Airport. National Airport is regulated so strictly that one is not considered necessary. Private pilot groups have vigorously resisted any new restrictions on their right to fly wherever they wish.

One reason the Dulles radar service area has caused debate is that as air traffic increases, private pilots are concerned that they will lose more of their privileges to fly where and when they want.

"Eventually, you have to decide whether you want to treat each plane as equal," said one employe of a major airline, "or whether you are going to create the equivalent of special bus lane that gives priority to public transportation."

"The bottom line here is that the radar service area is another way we have of enhancing safety at airports," said Dick Stafford, a spokesman for the FAA.

"We have tested it and talked to people and held meetings. Once pilots get used to it, they seem to adjust without any problem," he said.

Stafford said the FAA will consider changes to the proposed rules before deciding when to implement the system at Dulles.