Bills to carry airport construction grants and other aviation programs through the next four years are making progress on Capitol Hill, but they're far from complete and the clock is ticking. The programs, and the taxes that help finance them, expire Sept. 30. So far, chairmen of House and Senate tax-writing committees aren't saying what changes, if any, in aviation levies they support.

Senate Finance Committee Chairman Max Baucus (D-Mont.) says he wants to find "a good, fair, equitable solution." That won't be easy, because large airlines and general aviation groups representing those who fly smaller private planes and corporate jets are battling over how much they should pay in taxes and fees.

Senate Finance chairman isn't saying what aviation tax changes, if any, he favors. With current taxes lapsing Sept. 30, he knows he's "under the gun," but says he wants Finance to act before the deadline. If there's a snag, what about a stopgap? "I don't like extensions," he says.

With Sept. 30 nearing, Baucus acknowledges, "We're under the gun here." That deadline is "a real gun, with real bullets," adds Todd Hauptli, American Association of Airport Executives' senior executive vice president. Not only would new revenue to the Airport and Airway Trust Fund be cut off, but the fund's balance, $1.8 billion on last Sept. 30, won't keep things going for long.

Hauptli says, "If Congress allows the taxes to expire, you end up losing a construction season, for sure in the northern part of the the country, but potentially throughout the country." Baucus says he intends to meet the deadline. He also says he doesn't favor a stopgap bill. "I don't like extensions," he told reporters.

Action by the tax panels would be joined to aviation bills that have cleared the Senate Commerce and House Transportation and Infrastructure committees. Both bills provide $15.8 billion over four years for Airport Improvement Program grants, including $3.8 billion in 2008. This year's AIP appropriation is $3.5 billion. The House panel measure, but not the Senate version, raises the cap on passenger facility charges to $7, from $4.50. PFC proceeds fund airport infrastructure work.

The Senate commerce bill also has a $25 fee on commercial airline flights and about 10% of general aviation aircraft flights. "GA" interests oppose the fee. But Jay Rockefeller (D-W.Va.), who also is on the Finance Committee, said at a July 12 hearing of that panel that if the new bill doesn't "restore equity" among aviation users, he would seek ways to limit general aviation access to airspace in congested areas. In a blunt warning to general aviation, he said, "There are ways to do this, and we will find those ways."

Will Congress finish an aviation bill by Sept. 30? Steve Hall, American Council of Engineering Companies' vice president for government affairs, says that "there are some big issues to get through, but I think that [it's] something that will get done this year."