It was at the height of the COVID-19 pandemic when United Airlines executives greenlit an expansion of its pilot training center in Denver, United CEO Scott Kirby told a crowd Thursday.

United leaders were preparing for a full recovery, but Kirby said they had doubts as the rest of the airline industry was significantly scaling back.

Still, they decided to move forward on designing another building for United’s massive Denver campus.

And on Thursday, the 150,000-square-foot building for pilot training opened as travel demand not only recovered from the pandemic, but beat records.

“The official opening of the building is another milestone on the journey,” Kirby said at the ceremony.

Every nine months, United pilots have to come to the Flight Training Center in Denver to get recertified and make sure they’re up to date on safety procedures. The 23-acre campus in the Central Park neighborhood began construction in 1966 and has become the largest facility of its kind in the world. It’s the “center of the universe for United,” as the company’s CEO called it.

The new $145 million building also marks how the 56-year-old campus has run out of space.

Yet that’s not stopping the airline from expanding the Flight Training Center in its fastest-growing market.

“I don’t think we’re going to develop anymore here,” Jonna McGrath, vice president of United’s Denver hub, told the Denver Gazette. “The next development will be out on the land that we have out by the airport.”

The Chicago-based airline bought 113 acres of land near Denver International Airport for $133 million last summer and said some of that land will go toward more facilities that could start training pilots in 2028.

And the rest of the land gives the airline room to grow, McGrath said.

“We’re keeping our options open,” she said.

Meanwhile, the new building in Central Park — roughly the size of a large Target store — will expand the airline’s capacity to train its growing workforce of pilots with 12 more flight simulators. The machines are more than two-stories tall and are held by legs propping up the hull as it moves to simulate flying a plane.

United has 16,000 pilots and added more than 2,000 new pilots in 2023.

With pilot shortages rampant industry-wide, United is helping train pilots for their flying partners through its academy in Houston and the Denver facility, said United Captain and Training Instructor M’Lis Ward.

Pilots coming to Denver will go through training and will be checked that they can still fly safely, know different flying instruments and are put through real-life scenarios such as bad weather.

“That’s our way of making sure that not only can they handle an emergency on landing an aircraft safely, but they’re also doing the other things that are important,” Ward said. “And to me, the most important thing is keeping the passengers informed, keeping the flight attendants informed and making them a part of the team.”

With the additional building, United officials said the campus can host 32,000 training events yearly and train up to 860 pilots daily.

The pilots who visit are also spending locally. United pilots contributed $44 million for hotels in 2023, according to data from the airlines, and could spend $65 million in 2024.

The airline has made more than $1 billion in investments in Denver, which is one of its largest flying hubs.

In addition to the Flight Training Center and the land purchase, United has built new gates, clubs, and a check-in lobby at DIA. It hired 2,500 people in the area last year and plans to hire a thousand more in 2024, United said.

“Much like your kids, I’m not allowed to have a favorite hub,” Kirby told the crowd in the new Denver building.

Then the CEO raised his brows as the crowd cheered.