GREENSBORO Boom Supersonic searched nationwide for a place to build its jet factory and settled on an airport in North Carolina that is also a growing hub for aerospace companies.

At the heart of Piedmont Triad International Airport is a passenger terminal where four airlines offer about 35 flights a day, mostly to big cities like New York and Washington and airline hubs in places such as Atlanta, Charlotte, Chicago and Dallas.

But across the runways and around the edges, PTI is home to companies that build or service aircraft or ship cargo by air. More than 8,600 people work on airport property, and fewer than 10% of them are involved in moving passengers, according to Kevin Baker, PTI’s executive director.

“We have a dual-focused mission. One is wanting to provide the best possible passenger experience,” Baker said in an interview. “But the other component of this airport is this clear and laser focus on attracting the aerospace industry and the economic development that comes along with it, not only for this airport — not at all for this airport — but mainly for the region and the state.”

When Boom begins building the Overture, a passenger jet that will be able to fly faster than the speed of sound and twice the speed of today’s fastest airliners, it will become the second aircraft maker at PTI, after Honda, which builds small business jets. Meanwhile Cessna and HAECO Americas service, repair and overhaul planes, and FedEx operates its Mid-Atlantic hub here.

Altogether, the Triad region, which includes Winston-Salem and High Point, has about 200 aerospace companies, many with ties to the activities at PTI.

“They’re starting to get a true cluster of aerospace,” said John Kasarda, a business professor at UNC Chapel Hill who has written extensively about the economic impact of airports. “Once you reach a critical mass, which they have there, this tends to have a multiplicative effect, and then it has a momentum of its own.”

Kasarda coined the term “aerotropolis” to describe how airports could become hubs of economic activity, and he wrote a series of planning reports about PTI more than a decade ago. The first, written in 2007 for the Piedmont Triad Partnership, a regional business group, cited decisions by FedEx and Honda to locate there.

“There are signs of PTI and its environs becoming the new ‘downtown’ of the Piedmont Triad Region, the same way that the Research Triangle Park (RTP) has become the functional downtown of the greater Raleigh-Durham-Chapel Hill Region,” he wrote.

Baker said the PTI Airport Authority got serious about attracting companies to the airport in 2011 with a plan to acquire hundreds, and eventually thousands, of acres of land near its runways.

That meant relocating roads and buying homes and a golf course. When the N.C. Department of Transportation extended Interstate 73 nearby, it spent an extra $20 million to build a bridge the size of two football fields side by side that will one day allow planes to taxi from PTI to hundreds of acres of now vacant airport land.

Boom will lease 65 acres for its initial manufacturing plant, leaving PTI about 935 acres to market to other companies.

Baker says he used to fret that a company such as Boeing or Airbus would come to PTI seeking land that was ready for development near its runways.

“And if you can’t say, yeah, we got that, then you lose and they’re gone. They’re going to some other state or some other airport,” he said. “And so, our goal was to always be ready to say yes, to whatever that need is that somebody might have.”

Saying yes to Boom took help from state taxpayers.

A bill Gov. Roy Cooper signed into law in December provided $106.75 million for site development, roads and hangars at PTI needed to make the project work. That’s on top of an incentive package for the company worth $121.5 million from the state of North Carolina and Guilford County.

There were other attractions, including the Triad’s quality of life and relatively low cost of living, the interstate highways that converge on the region and the proximity to the coast, where Boom will test its supersonic planes over the ocean.

Company officials also singled out the region’s workforce. Once dominated by blue collar jobs in textiles, tobacco and furniture, the Triad has transitioned to aerospace and other manufacturing.

At PTI, Baker said, it started with Piedmont Airlines building a hangar in the 1980s to repair and service airplanes. To train the mechanics and technicians, Guilford Technical Community College established a campus at the airport that has grown to three buildings with new programs to give workers the skills Honda, HAECO and others need.

“You get to talking about what these companies really want and that is making sure that they can get employees. Making sure that the talent is there. Making sure there’s a pipeline to continue to grow that talent,” Baker said. “And what we’ve been blessed with since the late 1980s is that pipeline.”

As a passenger airport, PTI is overshadowed by the state’s two largest, Raleigh-Durham and Charlotte Douglas.

As a hub for American Airlines, Charlotte Douglas is among the 10 busiest airports in the world, with nonstop flights to 189 destinations, including 36 outside the country.

RDU is served by 12 airlines, including several low-cost carriers, which are eager to win business from the region’s growing population. More than 7.1 million passengers boarded flights at RDU in 2019, before the coronavirus pandemic, up nearly 42% from its previous pre-recession peak in 2007.

PTI’s business in 2019, of fewer than 1.1 million departing passengers, was slightly down from its pre-recession peak in 2008. It declined significantly more during the pandemic. The terminal, which dates to 1982, feels larger than it needs to be — several ticket counters are unused, and no more than a few of its 25 gates are occupied at a time.

PTI has turned all this into a marketing tool to try keep Triad travelers from driving down the road to RDU or Charlotte. “Fly easy” is the airport’s slogan, reflecting the ease of parking, checking in, getting through security and on a plane in an uncrowded airport.

“Everything is just a lot simpler to fly out of here,” Baker said.

There’s another benefit to not being a busy airport, notes Kasarda. The companies that use its runways don’t have to wait for an opening.

“It’s an airport that has plenty of flexibility in terms of takeoffs and landings and testing and so on,” he said. “They don’t want to put a facility where they really can’t test and where there’s congestion.”

Boom Supersonic expects to begin testing the Overture in 2026 and have the planes carrying passengers by 2029. The company says it will have more than 2,400 people working in Greensboro by 2032.

They won’t all be working on Overture, says Blake Scholl, the company’s founder and CEO.

“We were looking for a site that we’d have ability to grow on because Overture is just the start,” Scholl said in an interview with The News & Observer. “We’re going to be building multiple aircraft and keep getting larger.”

Boom is where Honda Aircraft Company was in early 2007 when it announced that it would manufacture its new HondaJet at PTI. The company had developed a prototype that was tested at the airport in 2003.

Honda didn’t deliver its first HondaJet until 2015. The company, which also has its corporate headquarters at PTI, produced its 200th jet in December.

Baker expects Boom will follow a similar path.

“It’s a start-up company. They’ve got a long way to go,” he said. “The development and certification of an airplane is not something that you do overnight. It takes a long time. And it’s got a lot of bumps along the way. But I see no reason to believe that they won’t succeed.”

In fact, Baker expects Boom will someday be using that airplane taxiway bridge over I-73 as it expands to the other side of the highway.

Honda received a reported $9.5 million in state and local incentives to open its manufacturing plant at PTI. A dozen years later, the company had about 1,900 employees at the airport, Baker said.

He says the state and local grants and tax breaks and government investments in the airport will come back several times over. The 8,600 people who work at PTI make an average $65,000 a year, or $559 million, he said, and that doesn’t count suppliers off-campus or how those wages are spent in the community.

North Carolina’s investments in aerospace haven’t always paid off. The state spent tens of millions to develop the North Carolina Global TransPark, a business park around an 11,500-foot runway outside the small eastern city of Kinston that remains largely undeveloped.

Kasarda, who conceived of the Global TransPark more than 30 years ago, said it didn’t take off mostly because of the lack of interstate highway access. But he says the state has done well attracting aerospace companies, including Collins Aerospace in Charlotte, GE Aviation in Durham and outside Asheville and Wilmington, and Spirit AeroSystems, which makes parts for Airbus fuselages at the TransPark.

“North Carolina is really a leader in aerospace development, but a quiet leader; you don’t hear much about it in the national media,” he said. “But if Boom achieves its expectations, you’re going to hear a lot about it. Because this is a high risk, high return venture.”