On the grounds of the St. Paul Downtown Airport, contractors and volunteer building trades workers are transforming an aircraft hangar into a year-round classroom for thousands of students interested in aviation.

It is an extraordinary effort, meant not only to whet the appetites of future pilots and aircraft mechanics, but also to give hands-on experience to dozens of apprentice plumbers, carpenters, sheet metal workers and laborers pitching in for a project with a budget of zero, said Steve Hurvitz, vice president of the Learning Jet.

“All the trades are here,” Hurvitz said. “Every time we’ve needed something, we’ve gone to the unions. And they’ve responded.”

Hangar 770A sits a couple hundred feet away from the Learning Jet, a former Federal Express cargo airplane that for the past two years has served as a classroom for students interested in science, technology, engineering and math. The Boeing 727, with working jet engines, also is used by aviation mechanics students from Minneapolis Community and Technical College.

While the big jet makes for an impressive laboratory, its parking spot on a sometimes-icy patch of tarmac, with only one nearby port-a-potty, leaves it less than ideal for wintertime lessons. Over the past year, Hurvitz said, the program has played host to more than 2,500 students from schools across the state. Next year, he said he expects 3,000.

So, about a year ago, officials with several St. Paul-area building trades unions began talking about what they could do to help. The idea of renovating the hangar was born and work began a couple of months ago, part of continuing efforts to use the St. Paul airport as a science and technology education center.

Dean Gale, business agent with Plumbers Local 34 in St. Paul, said it’s an easy project to support.

“The educational benefits to youth are great, with the STEM program,” Gale said. “And it’s a good cause for our young folks [apprentices] to work in that educational scenario. And it’s good outreach. Minnesota is home to a lot of tech companies, and we end up doing quite a bit of work when they remodel.”

The indoor bathroom in a Minnesota winter is another benefit.

“Now they won’t have to use the biffy outside,” Gale said, laughing.

Craig Rafferty of RRTL Architects volunteered to design the space, Hurvitz said. Home Depot contributed $18,000 worth of materials. ACA Inc. and York Heating and Air Conditioning contributed a heating/air conditioning unit and Nasseff Mechanical Contractors in St. Paul has agreed to work on the project.

Plumbers, laborers, sheet metal workers, bricklayers, cement masons, sprinkler fitters, carpenters and roofers all are volunteering to transform the hangar, which Hurvitz hopes to have ready by the end of the year. Carpentry students recently erected the 12-foot-tall metal studs that framed the inside walls. Plumbing has been roughed in.

At a time when more students are contemplating a vocational career, Dave Holzer of Sheet Metal Workers Local 10 in Maplewood said it helps to have real projects for them to hone their craft.

“We’re getting a lot more young people coming into the trade,” he said, adding that the union now has more than 400 apprentices.

When finished, the 3,400-square-foot hangar will also have a small kitchen and an instructional space where Hurvitz said a donated Piper Warrior aircraft will be used by students. He said he also hopes to eventually have a flight simulator or two.

The new space will allow the Learning Jet program to double the number of students it can host at any one time, he said, with half going into the jet and half in the hangar space.

On a chilly day last week, Hurvitz looked over all the work that has been done so far and nodded his head in appreciation.

“This is kind of amazing, really,” he said. “Everybody has bought into the program because it’s for the kids.”