There is a pig that flies, and it was an attraction Saturday at the Butler County Airport.
"It is a very awkward-looking airplane," Paul Luehring, a veteran of the Korean War from Beaver Falls, said of Thunderpig, a C-123K cargo plane from 1954 that saw duty in Vietnam. "But it's not heavy to fly. You can hold the yoke in one hand."
Thunderpig was the only improbable-looking machine at the Warbirds Experience, an annual event that showcases vintage planes.
This year, for the first time, event organizers landed a sleek P-51 Mustang, a fighter that came on line in the middle of World War II and was able to escort bombers all the way to their targets in Germany.
"It was a long-awaited fighter with speed, agility, an amazing airplane," said Jerry Kennihan, founder of the Warbirds event and president of Airquest Aviation, a flight service company at the airport.
The Mustang may have been one reason why the annual attendance of about 500 doubled before the event was 2 hours old.
It looked like Grand Central Station in slow motion, with people moving in every possible direction getting from one plane to the next. Little boys with crewcuts and dressed in T-shirts with planes on them strained at the hands of their parents like leashed puppies getting the scent of dropped bones.
T-shirts depicting aircraft themes also showed up on older and middle-age men in straw hats and ball caps, some walking with canes.
"We started doing this because we realized a lot of people don't even know this airport is here," Mr. Kennihan said. "The idea was to bring people in, let 'em have fun with old airplanes and acquaint them" with the airport. Airquest runs a charter service and flying lessons.
The Mustang and a World War II-era B-25 bomber, on which people could take rides Saturday, are privately owned by collectors in Virginia.
It was at this airport where Frank Franko's brother, Andrew, learned to fly in the 1930s.
"My brother was a B-17 pilot who was shot down over Italy in 1944. He died," said Mr. Franko, of Butler. "When he was 17, he hitchhiked to Texas to join the Army Air Force. My other brother worked out here. He joined the Navy. I was in the Navy.
"We used to play hooky from school to come out here just to hang out around an airport."
He was in the front of a crowd watching two Cessna trainers pirouetting. "I love them," he said. "I'll fly a Piper Cub once in a while."
Thunderpig is the pet of the group Air Heritage, based, like the plane, in Beaver Falls. Don Mansfield is the flight engineer for the pig, which has no innards, not even insulation.
It was made to haul 60 troops or 50 people on stretchers or five Jeeps and a two-ton truck. It was retired from military service in 1983 and now only flies to events where people who thought they had a clue about aerodynamics look at it long and hard.
Mr. Luehring, one of the pilots of Thunderpig, was a reconaissance pilot in a small plane in Korea, "taking pictures behind enemy lines," he said.
"I had a Brownie box camera and I had to put the stick between my knees to take a picture." So he knows about awkward.
"It takes two people to fly this plane for takeoff and landing," he said of Thunderpig. "Each one has to have control of the yoke and the throttle."
On behalf of Air Heritage, Ed Schmidt of Beaver Falls was taking $2 donations for people to walk through Thunderpig. He was in the Navy and flew a P-47 Thunderbolt in the Pacific during World War II.
"There aren't any P-47s here," he said. "Flying is still with me, but it's too expensive to keep up, which is why I come to things like this. I run into people and we get to talking again."