Philip Johnson and John Burgee, the internationally known New York architects who designed the controversial 52-story PortAmerica skyscraper planned along the Potomac River in Prince George's County, are no strangers to disputes over tall buildings.

Their International Place project on the Boston waterfront aroused opposition from preservationists concerned that the 46-story building would overshadow the historic Custom House district. But despite the preservationists' efforts, which included a protracted court challenge, the building is nearing completion.

The PortAmerica tower similarly is moving quickly to clear its official hurdles. It gained county zoning changes in 1983; the Prince George's planning board this month gave unanimous approval to the general concept, and county officials said the project is expected to receive final county council approval in June.

As the architectural landmark of the billion-dollar PortAmerica project -- which will also include hotels, waterfront restaurants, luxury housing and more -- the tower has drawn special criticism from federal agencies who argue it will overshadow Washington's monumental core, and from airline pilots, who have raised safety questions about its height and closeness to National Airport. It is the question of flight safety that opponents are now hoping can block the tower, but the developer is confident that this will not stand in his way.

James T. Lewis, a 53-year-old lawyer and the project's developer, brushes off the aesthetic criticisms and promises that any safety issues will be addressed this week as his consultants this week review flight patterns at nearby Washington National Airport with officials of the Federal Aviation Administration.

The FAA does not have the authority to block construction, officials there said, but it can declare the tower a safety hazard, affecting the developer's ability to secure liability insurance.

"If it does create a hazard, I can assure you it will be adjusted, insurance aside," said Lewis, whose firm is also building the Johnson-Burgee designed JTL Tycon Towers in Tysons Corner. "But I really don't think it does."

The FAA has studied the effect of other nearby high-rise buildings -- including the 31-story USA Today tower in Rosslyn -- on airport operations and almost invariably found them safe. None are as tall as the PortAmerica tower, but the Rosslyn high-rises are also near the flight path.

Working toward a summer or fall ground breaking on the first phase of the project -- a 600-room, 12-story hotel by the Beltway -- Lewis is seeking financing for PortAmerica. He is undaunted by tax law changes Congress is considering that would discourage multi-investor real estate syndicates, currently one of the major sources of funding for developers. He said he wants conventional financing instead and is talking to foreign banks that he would not identify.

In the event that the blanket loan for the entire project falls through, Lewis said he has been approached by two other domestic lenders interested in PortAmerica.

Lewis said he has invested $10 million so far in land acquisition and other start-up costs.

The PortAmerica project, including the tower, has been boosted by county officials who believe it will bring a new upscale respectability to Prince George's. Said County Council administrator Sam Wynkoop, scoffing at opponents from the District of Columbia, "We're going to require a neon sign on top that says, 'Welcome to the Monumental Area. Washington straight ahead.' "

Only a handful of county critics appeared at recent planning board hearings. They sought more bike paths and better shielding of a portion of PortAmerica from the adjoining neighborhood. But a court challenge of the project's zoning approval failed, even on appeal, muting local criticism.

V. Paul Zanecki, a prominent county zoning lawyer retained by Lewis said he is surprised by the unblievably mimimal" opposition.

"I get 30 people opposed to a dentist opening an office in his basement," he said. "A gas station will draw 300 people. A fast food establishment will close the county."

The biggest issue now facing Lewis and his skyscraper may be finding tenants in a glutted office market. But, even there, the developer is confident and outside observers give him a good chance.

Cheap, easy money for construction rather than the law of supply and demand has fueled a building boom in this area, according to Lewis Bolan, managing director of Leggat McCall Advisors, a local subsidiary of a large Boston-based real estate firm. But Bolan thinks timing may work to Lewis' advantage.

With tax reform, Bolan said, small developers who required a lot of investors will have a harder time getting financing, resulting in a drastic slowdown in new construction. By the time the PortAmerica skyscraper is ready to rent, Bolan said, vacancy rates will be dropping and rent rising.

"My feeling is Jim Lewis is a visionary," Bolan said. A lot depends on timing. He's banking on a pent-up demand for quality space in a quality environment. The views [from the tower] are spectacular, the access very good. Whether you want to call it visionary or spectacular, it's ambitious."

Lewis said he has already talked to a couple of major tenants "and a lot of small ones have expressed an interest." He described one potential tenant for the 1.1 million-square-foot tower as a "business machine computer-type" firm interested in renting 400,000 to 500,000 square feet.

And the developer also has an incentive up his sleeve. He has gained respectability for his project by winning the World Trade Center designation from the international association of world trade centers. But he has reserved the right to apply the name to either the tower or "a complex of buildings."

That way, Lewis said, "I can name the tall building after a certain tenant, say the 'XYZ Building.' That's very important" in recruiting high-profile tenants.

As the ego factor helped the developer obtain county approval, so it may help fill his building, according to Bolan: "He's doing some pioneering in location and depending on pizazz in design and height to sell the building."

For that, Lewis credits Johnson and Burgee, on whose recommendation he decided to include the skyscraper Burgee has called "a cathedral of commerce."

Burgee said some of his architectural peers have asked him to trim the tower but he has resisted their pleas.

"The problem of size comes up every time you go through redevelopment," said Burgee, arguing that as land values and property taxes rise so must the height of new buildings in order to shoulder the cost.

Opposition to International Place in Boston led to a lowering of height from 675 to 600 feet, compared with the 805-foot tower here.

"The obvious difference is that the Boston one is right in the city," Burgee said. "PortAmerica is seven and one half miles from the Washington Monument. It will be a bump on the horizon. If I thought it was awful, I wouldn't do it."