San Diego has settled on its plan to bring transit to the airport.

Regional leaders are going to ask the U.S. Navy to let them redevelop the Old Town property currently occupied by SPAWAR into a transit station with a rail connection to the San Diego International Airport.

Mayor Kevin Faulconer and Hasan Ikhrata, the new director of the San Diego Association of Governments, are championing the plan after it came out of a working group created last year to figure out how to finally connect the airport to the trolley system. Ikhrata will pitch the idea to the full SANDAG board Friday. Faulconer is attending to speak in support as well.

“It’s time to think big,” Faulconer said. “It’s a tremendous opportunity. There’s no better definition of a truly regional project and need than this. It’s been talked about for decades. It will require a lot of work in a quick amount of time, but the time is now.”

The project – they’re calling it “San Diego Grand Central” – would combine 70 acres of Navy property with the Old Town Transit Center. Trolley, Coaster and bus riders could take a rail-based people mover to the airport terminals, possibly through a tunnel running under the naval base and airport runway, though they’re considering above-ground options as well.

“We were just at the Boring Company two days ago,” Faulconer said, referring to Elon Musk’s company focused on improving tunneling technology. “We’re looking at the best that technology has to offer with one goal: How do we connect our transportation system to the airport?”

But the project would not just be a transit hub. It would have to include new state-of-the-art facilities for SPAWAR, the Navy’s cyberwarfare arm, totaling over 1 million square feet of space. The Navy would be an anchor for the project, but Faulconer and Ikhrata envision partnering with private developers to build housing, offices and retail space, in part to subsidize the project’s cost and in part to provide needed housing and job opportunities along the region’s trolley system.

After lots of talk but years of inaction on the need to connect the airport to the transit system, things now appear to be moving quickly. Ikhrata plans to have the concept fully sketched out for board approval by summer so the agency can jump into engineering and planning before the end of the year.

“We’ve done 10, 15 studies,” Ikhrata said. “There’s nothing more to study.”

In September, the Navy requested ideas for redeveloping its property, which is dominated by massive warehouses originally used to build fighter jets during World War II. The deadline for responses is Jan. 18; SANDAG is submitting the Grand Central concept as part of that competition.

Ikhrata said they’re also considering possible land swaps with the Navy – giving it public land elsewhere new facilities. But between the SPAWAR property and Old Town, the project area is almost 115 acres.

“It’s going to be one of the biggest economic development projects we can do,” Ikhrata said. “This has been going on for 40 years and finally (Faulconer) has said ‘enough.’”

What is not yet clear is how SANDAG, and all the other regional agencies involved, would pay for the project — or what it would cost.

The Airport Authority is trying to redevelop and modernize Terminal 1. Its initial proposal to do so did not commit to building an airport-transit connection, sending leaders from the Port of San Diego – which leases its land to the Airport Authority – the city of San Diego, county of San Diego, Metropolitan Transit System and other regional agencies into a tizzy.

Under heavy scrutiny, the Airport Authority pumped the brakes on its plan so that it could incorporate a potential transit connection. The mayor called for a summit of the various agency leaders and created the SANDAG-based working group that has now produced this proposal.

It’s expected that the airlines that call Terminal 1 home will shoulder the cost for the airport’s redevelopment, along with some portion of the new transit connection. And whatever public-private partnership materializes as part of the Grand Central concept will also account for a chunk of the project cost.

The remainder of the cost could come from a tax measure that MTS is shooting to put on the ballot in 2020, from SANDAG funds from TransNet, its existing sales tax for transportation projects, or from somewhere else.

Ikhrata said he wants to define the project before focusing on how they’ll pay for it.

“It’s going to cost money,” he said. “I believe there is the greatest potential for a public-private partnership. The airlines will be a big partner when it comes to financials, some private entities that are interested in having their systems there, some private developers who are interested in developing there. But no question about it, SANDAG will have to pay their fair share.”

He cited Los Angeles’s project connecting the airport to the regional rail system as an example, with airlines covering 60 percent of the cost and L.A. Metro paying a part.

Ikhrata and the mayor have already met with Navy representatives, and are doing so again Friday to get more specific. Ikhrata called them a “very willing partner” in the project.

The project would also include highway improvements to make it easier to reach the airport by other means. SANDAG’s working group studied new freeway connector ramps at both Vine Street and north of the airport, close to the SPAWAR facility, and improved access points on Grape Street and near Old Town State Park.

“It’s all linked,” Faulconer said.

Ikhrata said it’s not enough to just build a new transit station. The Coaster, the commuter rail line that would also feed into the new station, for instance, runs once or twice every hour. Ikhrata said it needs to run every five or 10 minutes.

“It’s more comprehensive than people think, which is why it’s regional in nature,” he said. “The transit option is the centerpiece. The highway option is also important. All of them as a package is going to make sure 3.3 million people in the county can access the airport with ease.”