21.   Silverstein Properties, which owns several office buildings throughout the city, wants to build three new towers on the site.

22.   Some real estate executives also questioned plans for a new tower while the vacancy rate in Lower Manhattan is in double digits.

23.   Such consolidation is also a response to community zoning regulations, which often prohibit the construction of new towers.

24.   The advent of digital television is also benefiting the antenna-tower industry, by increasing demand for new towers to accommodate new digital transmission equipment.

25.   The air traffic controllers are expected to use camera systems to give them a view of obstructed parts of the airport, until the new tower is built.

26.   The FAA is also building a new tower at Washington National Airport.

27.   The FAA disagreed, stating that any safety question concerning the new towers is a dispute between the union and management.

28.   The new towers should be up in five or six years, he said.

29.   The new towers have responsibility for air traffic on their respective sides of the airport, controlling three runways each.

30.   The new Enron tower will inject a significant amount of new momentum into downtown Houston, said veteran office broker Jeff Black of Insite Commercial Real Estate.