There are two gas-balloon builders in the world. One is in Germany. The other is Bert Padelt, of Berks County. Padelt holds world distance and duration records for the gas balloons he builds and flies. He's in Philly this week, but not to set a record. He plans to re-create one.

The first free-floating flight of a hot-air balloon with a human in its basket took place in 1783, outside Paris. (An earlier such flight's passengers included a duck, a rooster, and sheep.) Ten days later, also from Paris, the world's first hydrogen balloon took its first people up, up, and away.

Ten years later, yet another Frenchman, Jean-Pierre Blanchard, flew a hydrogen balloon from Philadelphia to Deptford, N.J. Way before the Wright brothers, this was the first flight in the United States.

This week, the Balloon Federation of America (BFA) is holding its annual convention at the Penn's Landing Hilton. Padelt expects 400 balloonists will attend. (One is the pioneering black hot-air ballonist Bill Costen. Read about him here.) The most visible part of the gathering will be a Friday-evening balloon glow, when inflated and lit-up hot-air balloons will colorfully fill the SugarHouse Casino parking lot.

The most historical portion, however, will take place Friday at sunrise (or, depending on weather, Saturday morning). That's when Padelt and former BFA president Sam Parks will reenact Blanchard's gas-balloon flight to mark its 225th anniversary. The event is called FAVIA225, which stands for "First Air Voyage in America."

Padelt spoke with us about the flight, ballooning basics, and his lifelong passion — and where to look for his balloon.

Ballooning: Not an everyday pastime. How did you get into it?

As far back as I can remember, I was fascinated with a little helium balloon or just a balloon filled with air. I'd imagine it was blowing with the wind, and I was attached to it, flying with it. When I was 13, I read a book about gas ballooning and learned you could fly much faster and at greater distances that way.

What's the difference between hot-air and gas ballooning?

A hot-air balloon gets its lift with hot air. You heat the air, the air expands and becomes lighter, and that's where you get your lift. To stay in the air, you need to continue to add heat to the envelope and keep the air at a consistent temperature. You do that with a burner that burns propane; however, this gives you a limited amount of flying time.

A gas balloon is made out of a different kind of fabric that will contain hydrogen or helium. The advantage is you can fly much farther. I've flown from Albuquerque to West Virginia in 50, 60 hours.

Tell me about that 1793 flight from Philly.

Jean-Pierre Blanchard came here especially to be the first person to fly a balloon in the U.S. His claim to fame was he was the first person to make a balloon flight across the English Channel.

Blanchard was a bit of a showman. He flew out of a prison yard [Walnut Street Jail] in Philadelphia because he wanted people to pay to come into the closed-in yard to watch him fly. But people didn't want to pay.

If you look at paintings of that day, you'll see people climbed trees so they wouldn't have to pay. Blanchard quickly realized how frugal people are in this country.

He spoke no English, so when he took off, he brought a letter from George Washington. The letter explained who he was, what he was doing, and asked that the reader to give this guy safe passage back to Philadelphia.

He flew across the Delaware over into Deptford, N.J. It was a very short flight.

What will your flight be like?

I built the basket — a replica — and the gas balloon, the Moonshine. We'll plan to fly out of SugarHouse at sunrise, to launch around 7:30 Friday. If the weather is not good, we have a backup of Saturday.

Will you be wearing period costumes?

The organizers would prefer that we did. But Sam [Parks] and I haven't discussed that yet.

Where will you fly?

The idea is to fly out of Philadelphia's airspace, taking off and flying north/northwest. That would be an ideal direction. Air traffic would be coming in from New Jersey, so we'd be flying away from all air traffic, and in a very short time, we'd be out of their airspace.

That would take us right back in to Bucks County, which has ideal areas for landing.

How does landing work?

You pick and area that is open — not planted, no crops, no farm animals. You don't want to land in a field that has livestock, cattle, horses, pigs.

When you're flying, you're always running the risk of trespassing. You're landing on someone's property, and you land there before the owner is there to ask permission. This time, we'll be able to radio ahead, to see if we have permission to land. In general, before you deflate the balloon, you ask the owner for final permission.

I've been doing this 40 years and can probably count on one hand the times a prop owner was upset.

So, what's the ballooning community like?

Ballooning is very much like boating, like owning a boat, owning a sailboat. The cost of a balloon is comparable to buying a Suburban, an SUV.

The sport attracts all kinds of individuals. Some balloonists are very eccentric. Some are very egotistical — ballooning has a way of feeding the ego because it attracts attention, even though the attention goes to the balloon itself. Schoolteachers, doctors, lawyers … Malcolm Forbes was a very good ambassador for ballooning, when he was alive.

What's your favorite flying moment?

It's incredibly beautiful when you're going through a sunset and you're at 10,000 feet, and the balloon is cooling, and you're ballasting, and you're watching the sun go down, and all of a sudden, it's dark and you're looking at the stars.

It's so quiet. When you're flying with your flying partner, you find yourselves whispering, and all of a sudden, you catch a falling star in the corner of your eye.

And there's a bonfire down below, and you flash your flashlight to them, and they yell up at you.

Blanchard reenactment flight, 7 a.m. Friday, free, SugarHouse Casino parking lot A (backup date: 7 a.m. Saturday). SugarHouse Balloon Glow, 7 p.m. Friday, free,