Federal Aviation Administrator Langhorne Bond Proposed yesterday "sweeping and comprehensive" changes in the air traffic control system that, he said, will make flying safer for millions of airline passengers.

Bond said the changes would extend extra protection against collisions in the air to airports serving 97 percent of the passengers on the scheduled airlines. At present, about 67 percent of such passengers are covered by that much protection.

The change would dramatically increase the amount of airspace over the United States that is "controlled" at all times and place more stringent limits on thousands of private planes and business pilots.

The changes, which would be implemented over the next few years, following the FAA's investigation of the Sept. 25 collision of a private plane and a jetliner over San Diego that killed 144 people.

A week ago Bond took the extraordinary step of, in effect, placing some of the blame for the San Diego disaster on his own agency. Yesterday's proposal is an attempt to apply the lessons of the San Diego crash to the air traffic control system nationwide.

Initial reaction to Bond's proposal yesterday broke predictably into opposition from the private pilot fraternity to praise from the commercial aviation industry.

J.J. O'Donnell, president of the Air Line Pilots Association (ALPA), called the change "a first step in the right direction." A spokesman for the Air Transport Association, Which represents most scheduled airlines, said "we're encouraged by the recognition of the need to increase" controlled airspace.

John L. Baker, president of the 220,000-member Aircraft Owners and Pilots Association, a private plane group, said the FAA "has failed to produce a workable air traffic control system and is using a tragic accident as the excuse to impose unnecessary restrictions which will hobble all of air transportation. . .."

Bond's proposal contains these important points:

A total of 44 more airports will be placed within blocks of airspace known as "terminal control areas." Only 21 such areas, containing 23 major airports, including Washington National, exist today. A pilot must receive permission from air traffic control to enter such areas, and his plane must be equipped with sepcific radio and navigational aids. No student pilots are allowed.

About 80 more airports, in smaller cities will be placed in blocks of airspace called terminal radar service area. Air traffic control is voluntary for pilots in such areas, but is available and about 90 percent of pilots traversing such areas seek the service, the FAA says. There are 105 airports in terminal radar service areas today, but many of them will be upgraded to terminal control areas.

The floor above which planes cannot fly without sepcific permission will be lowered from 18,000 feet to 10,000 feet east of the Mississippi River and in most of California, and to 12,500 feet in other areas west of the Mississippi.

Radar display units in airport towers will be improved to provide controllers with altitude readings and other infromation about the planes in their areas. The San Diego tower controllers did not have the improved radar display.

Twenty-four new instrument landing systems will be installed at nonairline airports in metropolitan areas. The private plane in San Diego accident was practicing on an instrument landing system at the main San Diego airport because that was the only such system available within 40 miles.

Some of the FAA actions can be accomplished administratively; others require formal rulemaking, which the FAA hopes to have completed by mid-1979. The entire package would be completed by about 1985.

Charles Spence, a spokesman for the private plane group, said that the combination of proposals is unacceptable to his group because it "sets aside so much space" that requires positive control. His group, Spence said, would restrict commercial airliners "to much narrower bands and put the burden on them." AOPA promised to fight the changes.

John Galipault, president of the Aviation Safety Institute, an organization that has continually prodded the FAA to make improvements, said that if everything Bond proposes works, "there should be a significant drop in near-misses, and this a drop in collisions." He questioned, however, whether the FAA's computers and controllers could handle the extra load the new procedures would require.

Bond said he is convinced the computers will be able to do the work. The cost of the equipment would be about $43 million. More than 300 controllers would be added in the first year and operational costs would be about $11 million. Funding has been approved by the Office of Management and Budget, officials said.

Every improvement the FAA has made in air traffic control has resulted in a reduction in near collisions, Bond said, and he predicted that his proposal would mean an 80 percent cut in near collisions above 10,000 feet.

He also said there will be "little dislocation" of the small-plane pilot from his present habits because of the proposed rules.

Galipault, of the Aviation Safety Institute, said that "as a pleasure pilot I don't like losing airspace, but in my position I have to support [Bond's proposals]. We have been recommending a lot of these things for years."