After spending two decades battling airport growth, residents living under Palm Beach International Airport's flight path are gearing up for their most challenging fight yet -- convincing federal and county officials that the airport's shortest runway does not need to be extended.

They have started their own Web site, enlisted a West Palm Beach transportation planner to help them analyze flight data and are using the Internet to spread messages about the project quickly.

Over the years, most of their fights to limit airport growth and noise have been unsuccessful.

An entire West Palm Beach neighborhood was demolished because the planes flying overhead were too loud. Four interchanges were built on Interstate 95 to carry passengers in and out of the airport, despite their protests.

But this time around, they say they are more organized and better positioned to fight.

"We have been doing this for so long, and we haven't quit," said Jim Young, a longtime West Palm Beach resident whose childhood home was lost to the airport.

"We just feel like we can't," said Young's wife, Lila. "There is too much at stake."

But the chips are stacked against them. And it appears unlikely they will be able to stop the project completely.

The Federal Aviation Administration began a three-year, $2.8 million environmental study of the extension plan in February. The agency doesn't conduct the costly studies, required for every airport improvement project nationwide, unless there is "a reasonable chance for success."

FAA officials say they cannot recall a situation where they denied an improvement project as a result of the environmental study. But a majority of them are modified before they are built based on information gathered during the review.

As part of the study, the FAA is required to consider a series of alternatives: relocating the runway, not building it at all or moving the entire airport someplace else.

But none of those alternatives is very likely, according to airport and federal officials.

Space on the airfield is limited, making it extremely difficult and costly to build a longer runway anywhere else there, airport officials said. Moving the airport would be even more expensive.

Meanwhile, a study released by the FAA this year shows that Palm Beach International is one of 18 U.S. airports that won't have enough space for planes if improvements aren't made by 2015.

Residents undaunted

Residents say they aren't dismayed by the discouraging statistics.

Jose Rodriguez, president of the Vedado neighborhood, which sits next to the demolished Hillcrest neighborhood, hopes to sway county commissioners to vote against the extension plan.

If the FAA signs off, the plan will be sent to the commission for final approval, airport officials said. The airport is owned and operated by the county.

"I think the county commission needs to take a deep look at this," Rodriguez said. "Right now, the commissioners are sleeping, and they just vote on anything that is fed to them."

Residents will get their next chance to sound off on the extension Nov. 27, when the FAA holds a public workshop to discuss alternatives to the proposed extension. The meeting will be from 5 p.m. to 8 p.m. at the Airport Hilton, 150 Australian Ave.

The project would extend the airport's general aviation runway from 3,210 to 8,000 feet, allowing it to accommodate commercial jets. Airport officials hope to open the new runway by 2014.

The extension would allow more planes to take off and land at the airport by creating parallel runways, one for takeoffs and one for landings. One plane could take off at the same time another is landing.

Aviation officials say it's the most efficient way to move airplanes because air traffic controllers don't have to worry about coordinating arrivals and departures on a single runway. A second commercial runway would allow planes to take off and land more quickly, reducing delays, they say.

"We continue to grow," county Airports Director Bruce Pelly said. "The city of West Palm Beach is going vertical on every block downtown, yet they look at the airport and say, why are you growing? We are in a position where we can almost double the capacity on that airfield."

Airport officials have maintained that the runway extension is needed to prevent lengthy delays, which could be up to 20 minutes long by 2018. The problems are during peak hours when multiple planes are trying to take off and land.

"We have got an issue now during the peak of the season where aircraft are sitting on the ground waiting to take off," Pelly said.

Sides argue over statistics

Those fighting the project, including Donald Trump, owner of the national historic landmark Mar-a-Lago, say noise and pollution from additional planes will harm the county's most historic neighborhoods.

They take aim at airport statistics that show growth in the number of flights and passengers using the airport.

Their chief complaints: The number of flights at PBIA is declining, and smaller general aviation planes could be relocated to the north county airport near Palm Beach Gardens and another in the Glades to free space at PBIA.

From 1990 to 2006, the number of flights at PBIA dropped 20 percent, according to federal records. During that time, the number of passengers grew from 5.7 million to 6.8 million.

"It's a significant decrease in activity," said West Palm Beach senior planner Alex Hansen, who has been working with Rodriguez and other neighborhood leaders. "What really creates the congestion is not the number of passengers, it's the number of operations."

Part of the reason for the decline is that many of the prop planes that used PBIA in the early 1990s were relocated to the north county airport when it opened in 1994, Pelly said.

"Just because the annuals are down doesn't mean the peaks aren't worse," he said. "We have eliminated a great number of the prop operations here. We built north county airport. All of that activity was going on someplace else."

Residents also are skeptical about the claim that passengers will be trapped in planes sitting on the runway if the expansion isn't completed. Most of the airport's use is from general aviation planes, such as corporate jets -- not commercial airliners.

"They are pitching this as people on commercial flights are going to be sitting and waiting," said Nancy Pullum, who lives in the historic El Cid neighborhood, which sits underneath the flight path. "It's not airliners. Sixty-five percent of the traffic is corporate jets and day jets. It takes as much airspace and time to land corporate jets and jets with 200 people."

Moving air traffic north

Unlike commercial airliners, general aviation planes do not have to pay a fee to land at the airport.

Residents say charging a fee could sway some pilots to use the northern airport. It also could be used to discourage flights during peak hours by charging pilots more to take off or land at those times, Hansen said.

Pelly said airport officials are looking to the north county airport as a reliever. The problem, he said, is that many of the general aviation planes that fly into PBIA are carrying Palm Beach residents who want to get home quickly.

"At the end of the day, if you've got the kind of money where you can afford the airplane, you want the airport closest to where you live," Pelly said. "These people aren't going to move their planes."

But with Palm Beach County's population growth slowing, the number of people who use the airport also could dwindle, nearby residents say.

Since 2000, the county's population has grown by about 25,000 annually, but in the past year that number has shrunk to 6,197.

Despite the drop, federal aviation officials project a steady increase in the number of flights at PBIA through 2025. This year, 198,627 flights are expected to take off and land at the airport. By 2025, that number is expected to grow to 280,846 -- an increase of 41 percent.

'Worse to get caught short'

Those opposed to the runway extension take aim at the projections, pointing to other forecasts did not come true.

A 1989 version of PBIA's master plan projected that roughly 8.3 million passengers would pass through in 1999. The number was expected to grow to 11.8 million by 2009.

But airport reports show that 5.7 million passengers used the airport in 1999 -- 31 percent less than the 1989 projection. Last year, the number was 6.8 million.

"They don't need the runway," said Jim Young, who grew up in the Hillcrest neighborhood. "What they said 10 years ago to justify what they have done already never happened."

Pelly, the airports director, said the master plans, which are updated every five years, look at the worst-case scenario.

"You've got to serve the public," he said. "It's a lot worse to get caught short."

But ultimately another airport between West Palm Beach and Orlando is needed to provide significant relief at PBIA, Pelly said.

"I've told everybody that I think at some point in time there needs to be an airport north of here," he said. "That's where the capacity relief is really going to come from. The problem is nobody wants an airport, but everybody needs it."

Staff writer Hector Florin contributed to this story.