THE PROBLEM that Tinicum Township residents have with Philadelphia International Airport is not the incessant roar of airplanes flying over their quaint, riverside community in Delaware County.

It's what is happening on the ground.

The airport, two-thirds of which already sits in Tinicum, wants to push farther into the town of 4,500 residents, gobbling up 150 of its homes and businesses as part of a $5.35 billion expansion plan aimed at reducing future flight delays.

Suburban opposition has reached a fever pitch in recent months, but the Federal Aviation Administration is expected any day to give the green light to the "Capacity Enhancement Program," a massive project 10 years in the making.

"If they take part of Tinicum, then what's next? Where does it stop?" asked Thomas Giancristoforo Jr., president of the township's board of commissioners.

"It's Philadelphia International Airport. If you want to expand the airport, that's fine and dandy. Expand into Philadelphia."

The project would take about 13 years to complete and create an estimated 45,000 construction jobs and 2,800 permanent jobs.

Its supporters include Mayor Nutter and airport CEO Mark Gale, who say adding a new runway and extending two others is crucial to the region's economic growth.

But Delaware County's local, state and federal elected officials are digging in, calling it a $5 billion Band-Aid that isn't worth the cost.

The expansion, aimed at reducing the average flight delay by about 14 minutes in 2025, calls for acquisition of 72 homes and 80 businesses in Tinicum.

Giancristoforo said the lost tax revenue could cripple the Interboro School District, which covers Tinicum and three neighboring boroughs.

The district would lose about $2 million a year if the plan goes through, according to the FAA's most recent report. Residents also fear it could threaten the viability of Tinicum School, an elementary school that was one of only 300 National Blue Ribbon Schools this year.

"It's going to devastate both Tinicum Township and the Interboro School District," Giancristoforo said.

Dee Waldeck, who lives on Manhattan Street in the neighborhood that would be razed by the airport expansion, doesn't want to leave. Neither do most of her neighbors, who have stuck "Not For Sale" signs on their lawns in protest.

"It's a great little community and we're going to do whatever we can to try to save it," said Waldeck, 50, a school-bus driver.

Waldeck moved to Tinicum 24 years ago so that her husband, who frequently traveled for work, could be close to the airport.

She never imagined that, with their two kids now heading to college, the airport would try to force them out.

"It's very disheartening," she said.

In addition to the growing suburban resistance, U.S. Airways and Southwest Airlines have objected to the project's costs, the former also arguing that building a new runway without addressing airspace congestion would make both the airport and airline "less economically viable."

Dave McCann, president of Residents Against Airport Expansion in Delco, says a true "regional" approach would include the use of underutilized airports in the area, rather than simply cramming more planes into Philadelphia.

But airport spokeswoman Victoria Lupica said industry deregulation in 1978 gave airlines the right to choose where they operate.

"Airports cannot require or direct airlines to service a particular airport or market," she said.

McCann, who lives in Tinicum, sees it differently, calling the expansion a shortsighted sham to funnel more money to the city at the expense of its neighbors.

"They're trying to suck every single dime out of every single person and plane that they can," McCann said. "It's all money oriented for the city. It has nothing to do with regional planning or anything like that."