Anyone who's ever seen them from afar, drifting over the landscape, knows hot-air balloons can seem otherworldly. But anyone who's ever flown, helped fill or gone for a ride in one knows that it takes a lot of earthly labor to get them airborne. Commercial balloons must be able to safely lift at least 2000 pounds -- gondola, burner, propane tanks and passengers -- hundreds of feet in the air. And, just like automobiles, they are subject to regular maintenance checks.

Balloon mechanic Paul Stumpf has been building and repairing these buoyant baubles for more than three decades. He ran his own FAA-certified balloon repair station in Rhode Island, then moved to Vermont six years ago, partly in response to a downturn in ballooning as a leisure sport. Stumpf calls himself "a one-man band" -- he works by himself, and is one of just six full-time balloon maintenance people in the U.S. As the operator of the state's only year-round repair station, he caters to 70 customers: pilots from New England, including Vermont's dozen or so hot-air aviators, and those who pass through regularly on their way to different balloon festivals. Upcoming air carnivals include the Vermont Balloon and Music Festival in Essex Junction on the weekend of June 2, the Quechee Balloon Festival two weeks later and, in July, the Stoweflake Hot Air Balloon Festival.

Stumpf has a snug workshop on the top floor of an old hay barn on the Andover-Weston Road. Lining the walls are four industrial sewing machines, each of which is calibrated to a specific style of stitch. Scores of colorful posters and photos of airborne ovoids cover the sloping ceilings.

SEVEN DAYS: To what extent are you regulated by the FAA?

PAUL STUMPF: Essentially, the FAA requires you to establish a system for what you do. As a balloon repair station, you have to write a manual . . .The same [procedure is] required . . .for Boeing working on jetliners. Once you've got that approved, you have to do physical training. The usual way is that you work for another repair station for at least six months, full time.

SD: Who did you work with?

PS: [laughs] I did it back when there were so few balloon repair stations, there was nobody that I could go work for for six months. I got into it sort of backwards. I actually built a balloon when I was in high school.

SD: Oh, really? Wow.

PS: When you build your own aircraft, you automatically get a repairman's certificate to maintain your aircraft . . . I basically said, OK, I've built five of these things, and I've been doing this for five or six years. I know everything about building balloons and how they're made, so would you accept that as my training?

SD: When did you start repairing balloons as a business?

PS: Luckily for me, I got involved in the mid-'80s. I rode the wave [of ballooning as a hobby], and got all of these people trained how to fly. They became my customers. I also started a mail-order business of balloon equipment . . . for instance, a padded cover for [the propane tank], in case you bump up against it on a landing.

SD: And the mail-order catalog is a year-round thing?

PS: Yeah, because there's always somebody flying. It was originally stuff that I built, like these big storage bags that the balloons go in, and bags for the burners. And then I got sidelined into carabiners that balloonists use, and helium tanks and books. Whatever I felt balloonists would like and find useful.

SD: What got you into balloons in the first place?

PS: The art teacher at my high school decided to build his own balloon. He had the art students helping him paint designs on the balloon fabric, and we actually helped him weave a basket. And I thought, "Oh, this is cool." So I'm, like, 16, and saying, "Hey Mom, I'm going to build a balloon."

SD: And your parents were OK with that?

PS: Well, they were like, "Oh, OK, sure." Then the next thing they knew there were big, 20-foot things of wicker and rolls of fabric arriving on trucks, and I was borrowing my friend's mother's sewing machine. I don't think they really believed it until we were ready to go and fill it up.

SD: Is it hard to make repairs that are effective and also look good? I'd imagine how a balloon looks is pretty important to its owner.

PS: Yeah, it's an aesthetic thing. There is an incredible amount of finesse in doing a safe balloon patch that looks nice when it's done, and has the proper stitch length, thread and material.

SD: How often do balloons need to be inspected?

PS: They're treated the same as an airplane or a helicopter. They have an inspection either every calendar year or every hundred hours of use.

SD: How do holes happen? Do the seams just give way?

PS: Mostly they get burned from the burners, or torn on trees or other sharp things on the ground, like a fence or a lightpost. You can put balloons into some pretty tight spots. The fabric is pretty amazingly durable.

SD: Does the fabric get brittle?

PS: As it gets older, yes. Fabric strength is one of the primary things that we check each year. We look for the worst fabric in the balloon, up in the top where it gets the most sun and the most heat. All of the owners hate it. It's like going to the dentist. We put these awful clamps on.

SD: So basically, you're trying to tear the fabric?

PS: We pull it to a minimum strength requirement, which certifies it for another 100 hours. It's called a tensile test. You pull to a certain number of pounds of tensile strength, and, if it passes that, it's good for another year . . . If somebody comes in and it tears at 20 pounds, it's not necessarily the end of the balloon. Maybe you can put a new top in, or maybe it was just one of the colors, because every color responds differently. You work within the constraints of the pattern of the balloon -- specific gores, or panels. If a brand-new balloon got in an accident, I could reproduce the panels exactly and sew them in so even an experienced balloonist would never know that it had been repaired.

SD: Balloons can come in complicated shapes. Do you have a favorite shape to work on, or any that you dread doing?

PS: I hate special-shape balloons [laughs]. Just because the hole can be seen doesn't mean that you can get to it with a sewing machine. Internal structures hold the shape, and I have to disassemble those to get out to all of the appendages, where the little legs and things are. So the shape balloons are very tedious to work on.

SD: They look cool, though.

PS: They look great, and I have nothing but praise for the people who build them. They're amazing.

SD: Do you still build your own balloons?

PS: I've been really trying for about five years to make a balloon that would be able to lift myself and one other person, and only weigh about 65 or 70 pounds. I'm big into mountain biking, and the ultimate goal is to have everything retrievable by two bikes. So that's my pet project.