WASHINGTON (CNN) -- All critical components of the air traffic control system -- responsible for controlling 75,000 flights a day nationwide -- have been adjusted for the year 2000, federal aviation officials said Thursday.

The officials sought to assure the public that air travel will be safe in the United States at the turn of the century.

The Y2K problem is caused by the inability of computers to distinguish between the year 2000 and the year 1900.

The Federal Aviation Administration said it had made repairs to 65 systems involved in air traffic control. Of those 65 air traffic control systems, 57 (88 percent) have successfully passed tests to ensure their safety, and the remaining systems are "on track" to be tested by a March 31 deadline, FAA's Ray Long said.

But air travelers could experience other problems stemming from the so-called Y2K bug but unrelated to air traffic control, Long said.

"The impact could be more on the infrastructure -- how you get to and from the airport," he said.

Travelers could also experience other problems -- such as baggage handling back-ups -- if those systems are not checked and corrected by individual airports, he said.

Power failures, if any, would not affect air traffic control operations, he said. "We have power failures today and it's seamless to the controllers because generators kick in and provide power."

FAA officials say they are conducting tests of FAA computers that interact with other systems, and the FAA needs to "make sure that data is properly transmitted through these interfaces."

In order to demonstrate their confidence in the U.S. air traffic system, Long and FAA Administrator Jane Garvey say they plan to fly across the country on a commercial airliner on January 1.

Of greater concern to the FAA -- the air traffic control systems of other nations.

The FAA is conducting tests with the top six international destinations of U.S. flyers -- Canada, Japan, Mexico, the United Kingdom, the Bahamas and the Dominican Republic. And both the FAA and international aviation organizations are working with other nations in an effort to bring them to Y2K compliance.