The space shuttle Enterprise, perched atop a 747 transport jet, will make a low-level display flight around the Capital Beltway and up the Potomac River Sunday morning before landing at Dulles International Airport.

The Enterprise, a prototype that has never flown in space, will be on display at Dulles until 8 p.m. Sunday. Officials predicted yesterday that more than 250,000 people will travel to the airport to see it.

Flying at about 2,000 feet, it will arrive at the Beltway near the Woodrow Wilson Bridge about 10:10 a.m. and will fly around the 60-mile highway. It will then turn up the Potomac, fly to Cabin John and head for Dulles, touching down at about 10:30 a.m.

It will be coming from the Baltimore area, where it will make a similar fly-over beginning at about 9:30 a.m.

Dulles spokesman David Hess predicted the highway to Dulles will be jammed on Sunday and advised anyone trying to catch a flight from the airport that day to start early.

An 11,500-foot runway there will be closed to airplanes and devoted to parking on Sunday, Hess said. Spectators will be allowed to come within 200 feet of the spacecraft but will not be allowed inside. Access highway lanes leading back into the city will be closed, with cars being directed onto Rtes. 7 and 50 instead.

The Enterprise recently completed a tour of Western Europe that included Bonn, Rome, London and the Paris Air Show. The NASA spokesman said that the agency felt the spacecraft should get more domestic display and that Washington was an appropriate place to begin.