GRAND RAPIDS, Mich. — Julia Stevenson scurried through the hallway as her school day came to a close, hoping to take advantage of as much daylight as possible to complete one of the last assignments of her high school career.

“I’m flying home today,” Ms. Stevenson, 18, said with a broad smile, explaining that she was hoping for clear skies and a beautiful view of Lake Michigan on the 300-mile round trip from Gerald R. Ford International Airport to her hometown, Traverse City, Mich.

With her pilot’s license in sight, Ms. Stevenson was about to graduate from the West Michigan Aviation Academy, a public charter school here founded by Dick DeVos, the billionaire husband of Education Secretary Betsy DeVos.

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Ms. DeVos has called it an inspiration for her dogged support for school choice, a shining example of what is possible when schools are able to meet students’ unique interests and needs. On Tuesday, she told thousands of charter school advocates that her husband’s school prepared students “to contribute in significant ways to our 21st-century economy.”

But with its deep-pocketed founder, corporate sponsors and remarkable capacity to raise money, the Aviation Academy may be more an example of what education can achieve with seemingly limitless funds than a model for other schools.

Like the neighborhood public schools of Grand Rapids, the academy, on the grounds of Gerald Ford Airport, receives $7,500 per student in state funding. This helps pay for its rigorous science, technology, engineering and mathematics, or STEM, curriculum and its faculty, including the four flight instructors on staff.

But it does not pay for the school’s two airplanes; many of its science, engineering and mathematics facilities; or its distinction as the only school in the country that offers flight instruction as part of the curriculum. Students can graduate and fly a plane before they can rent a car or legally have a beer.

How? The DeVoses alone have given more than $4 million to the school. Mr. DeVos donated an airplane from his private collection. Delta Air Lines donated another.

“The concept is good. I just wish a public school would’ve thought of starting that rather than have it be a charter,” said Mary Bouwense, president of the Grand Rapids teachers union. “But I guess we wouldn’t have been able to afford it. You have to have a boatload of money to start a school at the airport.”

The school, publicly funded and privately operated, is representative of the tensions in the school choice movement that have grown under the Trump administration.

Ms. DeVos and Mr. Trump are proposing to increase funding for public charters, which serve more than three million students nationwide, by $168 million, or 50 percent, while cutting total education funding by $9 billion, much of which would come from programs primarily for traditional public schools.

While charter schools have long had bipartisan support — they have been championed by every president since Bill Clinton — the movement finds itself at a crossroads. Charter school advocates have long said they support traditional public education as well, but the Trump budget has presented them with something of a choice: us or them.

“The president has given a big hug to charter schools at the same time he’s slapped down other education priorities,” Nina Rees, president and chief executive of the National Alliance for Public Charter Schools, told a gathering of more than 4,000 charter leaders and advocates this week. “All of us need to understand that accepting the president’s support for charter schools doesn’t tie us to his whole agenda.”

The Aviation Academy has been at the center of similar debates in Michigan. The DeVoses backed the state’s first charter legislation, passed in 1993, and their support for expanding charter schools has been seen as a direct threat to public schools, particularly vulnerable ones in cities like Detroit.

On Tuesday, Ms. DeVos praised charter schools for proving that “quality and choice can coexist,” but said they “are not the one cure-all to the ills that beset education.”

Ms. DeVos encouraged her husband to start the school after he lost a run for Michigan’s governorship in 2006. It would combine two of his passions — education and flying.

Since then, the academy has attracted a diverse pool of 600 students via lottery. One of the recipients of its C.E.O. award this year was a refugee who enrolled in ninth grade speaking only Swahili. It outperformed traditional schools on state tests this year and has a four-year graduation rate of 85 percent.

Students shoulder some costs, like extra blue polo shirts for their uniforms, insurance for Chromebooks and a fee for flight instruction. But the school primarily supports its aviation program with fund-raisers, including an annual banquet, which have drawn guests of honor such as former President George W. Bush.

The DeVos name “doesn’t hurt,” said the school’s chief executive, Patrick J. Cwayna, a former Grand Rapids public school principal whom Mr. DeVos selected to run the academy.

“Why wouldn’t we use their positive influence to bring advantages to our kids?” Mr. Cwayna asked.

Ms. Stevenson hopes that does not change. She has wanted to be a pilot since age 6 and never imagined that she would be able to take her family flying to celebrate her graduation. To attend the Aviation Academy, she has lived with family friends since she was a sophomore, one of a number of students who come from miles away.

While Ms. DeVos has no direct role in running the school, Ms. Stevenson said it had become a target of critics since she became secretary of education.

“There’s a lot of politics to it, but for me, personally, it’s been an awesome opportunity that I’ve been able to take advantage of,” Ms. Stevenson said. “I don’t see why that’s a negative thing. We’re just a bunch of kids pursuing our dreams.”

The school started with 80 students in a renovated conference room at the airport, and has since tripled its population and nearly doubled its size. Its student body is 34 percent non-Caucasian and 10 percent special education, and this year, it drew 282 applications for 155 spots, including two applicants in their 30s.

Mr. Cwayna said Mr. DeVos did not push his political or policy views on the school’s leadership. He has made only two requests based on personal preference: that it not call the parent group “the PTA” and that the men wear gray pants, a light blue shirt, dark blue blazers and one of three ties.

Mr. DeVos is currently guiding the school through another expansion. At a recent board meeting that he led, members mulled over plans to add new facilities, including an airplane hangar, commons and classroom.

Mr. DeVos smiled often but said little. Then he was presented with the growing number of students on the waiting list.

“Well,” he said. “Waiting lists always bring mixed feelings.”