Virginia Hale was working at her desk on the 28th floor of the Twin Towers office building in Rosslyn late last month when something looming outside her window caught the corner of her eye.

Just in time, she turned to see an enormous Piedmont Airlines Boeing 737 passenger jet thunder past just below eye level, seemingly less than a football field away.

"It was close; it was very close," Hale said. "It looked like it was circling the building."

The incident Hale witnessed on Dec. 28, which was viewed by dozens of others in Rosslyn, has sparked a new debate about how safely planes are able to navigate the forest of office buildings on their way to National Airport, particularly during poor weather.

Among those plainly worried is Westfield Realty, the firm that manages the 31-story Twin Towers. Westfield's Brad Goodnough said the firm has requested a meeting with the Federal Aviation Administration and the manager of National Airport's control tower to find out whether the plane violated air-traffic regulations.

"There's no way they could have been in compliance," said Goodnough, based on what he has heard from building tenants.

The incident is being checked by the National Transportation Safety Board, which says it is examining the Piedmont jet's flight recorder to find out whether the aircraft came in too low and whether it flew over Rosslyn, as witnesses said, or along the river, the normal route.

The FAA already has said it believes the jet was on a normal flight path.

As for Piedmont, the airline initially said the flight approach appeared normal. But Piedmont since has declined further comment until the NTSB completes its examination.

Arlington County Board of Supervisors member Dorothy Grotos said the board frequently receives complaints about low-flying planes from Rosslyn residents and office workers.

"When they see people sitting in their seats [on the plane], it seems too close for comfort," she said.

But Grotos said she does not expect the board to take up the issue because of the FAA's determination. "They say everything was proper. I guess we have to take their word for it," she said.

The FAA reviews all proposed construction above 150 feet in height near the airport. Although the agency does not have the power to stop a structure from going up, its recommendations carry weight with local zoning authorities.

In the case of the Twin Towers building and all other Rosslyn high-rises, the FAA determined they would not be hazardous.

"In Rosslyn, we found that the buildings were well separated and well beneath the course serving National Airport," said Jim Hennessy, an airspace specialist for the FAA.

The only time the FAA was concerned was during construction when cranes were atop some buildings, he said. Pilots at that time were told to stay at a higher altitude as they passed Rosslyn on their approach to National.

A spokesman for the Airline Pilots Association, who asked not to be identified, said that when some Rosslyn high-rises were proposed several years ago, his organization informally asked the FAA to recommend against construction. "We said our preference would be that they did not locate buildings there," he said.

The pilots association believes high-rises along the Potomac River "reduce the cushion of airspace the pilot has to maneuver in" and create a "funneling effect as you get closer to the airport," he said. The extra airspace would be needed only if something went wrong, he said.

After examining recorded images from the airport's radar in the Dec. 28 incident, the FAA said the plane had made a normal instrument approach into National Airport. The agency said it may have appeared the plane was headed into the Twin Towers building because the pilot had pointed the nose of the plane off-course to compensate for a crosswind. To those who saw the jet, however, it is another matter.

Jess Randall, a former 23-year Marine pilot, had one of the best vantage points in Rosslyn to watch the Piedmont flight. Randall and his boss were in a 23rd-floor penthouse conference room of the Rosslyn Center building on North Moore Street when they heard the jet approaching.

"All of a sudden, my boss . . . jumped up and said, 'Oh, my goodness!' The aircraft looked like it was coming down Moore Street," Randall said. "I looked out and I was looking down on the wings."

Jack Young, down the hall at the Rosslyn Center, watched as the jet passed the Twin Towers building a block and a half away. "The plane was halfway down the building going past it," he said. "The plane was down that low and the pilot was throwing the throttle, trying to get altitude."

On the 28th floor of the Twin Towers building, in an office with a Potomac River view, Imogene Rudnick, a secretary, was taking dictation from her boss, Wilfred Medley, when the jet passed. "It was just below the window," said Rudnick.

Medley, an underwriter for New York Life, said he was "so shook up and so frightened" by the incident that he called the airport. Planes have come close to the building before, he said, but never as close as the Piedmont flight.

"Anytime it's cloudy or overcast they seem like they're taking the top of the building off," Medley said.

Added Rudnick: "It was terrible. This was a terrible blunder on somebody's part."