The operators of Plattsburg International Airport, in upstate New York, used $12 million in AIP funds to outfit the former Air Force base with better runways, a state-of-the-art landing system and a new terminal. These improvements helped lure aircraft engine manufacturer Pratt & Whitney, as well as the Department of Homeland Security and other tenants.

Former airport manager Ralph Hensel said Plattsburg also is hoping to lure commuter traffic from nearby growth-restricted Clinton County Airport, and possibly entice scheduled service by commercial carriers.

Scores of other small airports spent millions on runway extensions, lighting and updated landing systems that airport managers say were not specifically for the benefit of private jets and business aircraft, but do lend themselves to such uses.

Congress now is considering new approaches to financing the FAA before its funding expires Sept. 30. The House and Senate Aviation Subcommittees have been conducting hearings on the topic since February.

The FAA wants to scrap many existing passenger taxes and replace them with higher fuel taxes and user fees that would put more of the burden on noncommercial aviation.

"We will need to invest resources in order to make the transition to a new system that will significantly reduce operating costs and better serve our customers in the long run," FAA administrator Marion Blakey told a Senate subcommittee on aviation in February.

But pilots' groups, business aviation organizations and small plane manufacturers are fighting the agency's proposal.

Bolen, the National Business Aviation Association president, said the nation's entire aviation infrastructure is geared toward commercial air travel and cargo.

"It's like going out to dinner and somebody buys the most expensive stuff and then says, 'Hey, let's divide this up among all the diners,"' he said. "Who should pay for that?"

Commercial airlines support the proposed changes and say private aviation has been collecting huge taxpayer handouts that should go to airports that serve the general public.

"We're saying users should pay in proportion to their share of system use," said Heimlich, of the Air Transport Association. "The current system isn't priced rationally."

The scrutiny from lawmakers comes ahead of a planned overhaul of the nation's aging air transit system. Air traffic is predicted to grow by more than 25 percent over the next decade, and experts say the growth will be driven by a proliferation of smaller passenger planes and private jets.

The ambitious overhaul will replace existing ground-based radar with satellites and is expected to cost $22 billion — maybe more.