EVERETT — As opponents try to foil Paine Field passenger air service in court, a private investment firm is trying to make it a reality.

New York-based Propeller Investments has asked Snohomish County, which owns and operates the airport, to start discussions leading to construction of a terminal and parking facility at Paine Field.

The private equity firm doesn’t have a formal proposal, but on Tuesday, its CEO and founder Brett Smith spoke about a possible arrangement in which it would shoulder the risk — leasing land from the airport, financing terminal construction and finding tenant airlines.

“We’re very flexible,” though, Smith said. The company is “willing to work within the confines that work for the county.”

In a short letter dated Monday, he asked county officials to start talks within 30 days.

Passenger air service at Paine Field will encourage economic development and give travelers here a more convenient and cheaper alternative to Seattle-Tacoma International Airport and Bellingham International Airport, he said.

Propeller Investments envisions four or five commercial flights a day to regional destinations, such as Spokane, Portland, San Francisco and Los Angeles or Long Beach, he said.

Paine Field handles about 300 flights a day, ranging from small single-engine airplanes to big Boeing jetliners rolling out of the Everett assembly plant, which abuts the airport. That is about one-third of the airport’s flight capacity, said Dave Waggoner, the Paine Field director.

Smith said, “The airport fits our business model of developing regional, niche airports.”

Founded in 2008, Propeller Investments is developing an alternative to Atlanta’s commercial airport, one of the busiest in the world. Its executives and advisers have extensive experience in running, overseeing and working with airports and airlines, according to its website.

He said the market could support regional travel, but “you’re never going to see flights to New York or Tokyo.”*

Opponents don’t want to see any passenger flights at Paine Field and were headed to federal court Wednesday to challenge a Federal Aviation Administration conclusion that noise, traffic and pollution from commercial flights would not hurt nearby communities.

Mukilteo is leading the challenge in the 9th U.S. Circuit Court of Appeals, along with the city of Edmonds and an activist group of residents, Save Our Communities.

If they succeed, the FAA would have to do further analysis, likely delaying attempts to bring passenger flights to Paine Field.

It could take several months for the three-judge panel to issue a decision.

In the meantime, Mukilteo Mayor Jennifer Gregerson said, “Proponents of air service should understand that it is important to let our case take its course.”

Proponents include Everett Mayor Ray Stephanson, who issued a statement supporting Propeller Investments on Tuesday.

“After years of debate, it’s time to take advantage of this opportunity and move forward with a plan that helps our economy, builds on our aviation foundation and provides easier access to air travel,” he said in the statement.

Snohomish County will contact Propeller Investments to discuss the proposal, said Rebecca Hover, a spokeswoman for the county executive’s office.

Whether or not to partner with the company would likely be a decision for the Snohomish County Council.

Talks about a passenger terminal last year between the county and Allegiant Air reached an impasse. The county proposed to build a publicly owned terminal for about $3 million and recoup construction costs from parking and concession revenue. The airline wanted to build, operate and own a terminal on lease-free land.

The Las Vegas-based airline remains interested in Paine Field and other sites as well, said Jessica Wheeler, a company spokeswoman.

Allegiant and Alaska Airlines are the only two carriers that have expressed interest in serving Paine Field in recent years. Alaska had said it would be interested only if another airline established service first.

Today, “there are a number of airlines interested” in Paine Field, Smith said.

But he couldn’t publicly name any, he said. “They’d kill me if I put their names out there.”

Dan Catchpole: 425-339-3454; dcatchpole@heraldnet.com; Twitter: @dcatchpole.

Correction, June 18, 2014: Brett Smith of Propeller Investments said he believes Paine Field can support a single terminal with up to to gates. An earlier version of this story misstated how many terminals he foresees at the airport.