"He was shot at a lot," Berthelsen said, "but never shot down."
During World War II, the Manchester airport, known then as Grenier Field, ceased civilian flights and became focused on the war effort, becoming a major location for troops for deployment to Europe.
"Most flights to Europe were out of Manchester," Berthelsen said.
There are so many years with so many stories related, he said. That's what makes his volunteer work at the museum so rewarding.
Families with ties to rich New Hampshire aviation history have offered valuable collections of artifacts to the museum.
"We take books, news archives, anything related to New Hampshire," Berthelsen said. "We have an extensive library."
Some items were found by accident. A major exhibit right now is the "Doodle Bug," the first biplane designed and built in New Hampshire. A main structure was first discovered, but the wings came decades later, after being found in a barn.
"Then we found more parts in a Rochester hangar," Berthelsen said. "The wings were all covered with pigeon droppings."
It's one of his favorite exhibits.
The museum also supports the future of aviation, offering educational classes for high school students who are interested in learning about flying. Right now, the program is open to students in Londonderry, Exeter and Manchester, who come three days a week.
Berthelsen said the nearby airport assists in the program to help students see what happens behind the scenes.
"This is something the museum and Society is really focused on," he said. "It's a fabulous program and they get to learn all about aviation."
Berthelsen said it never gets old when it comes to talking about the state's aviation history and those who made the grade when it came to flying.
"Our goal is to have everybody learn something when they come here," he said. "And the best part is, we learn something, too."
The Aviation Museum of New Hampshire is located at 27 Navigator Road. Call 669-4877 for information or visit the museum at nhahs.org.
The museum is open Friday and Saturday from 10 a.m. to 4 p.m., Sunday from 1 to 5 p.m., and by appointment.