CINCINNATI -- Risking death every time they go to work, wing walkers need courage, poise, a healthy craving for adrenaline and, most importantly, they need to be meticulously exacting with every step they take on the small planes that carry them past dazzled crowds at speeds up to 130 mph.
Jane Wicker fit that bill, her friends and colleagues in the air show industry said Sunday.
Wicker, 44, and pilot Charlie Schwenker, 64, were killed Saturday in a fiery plane crash captured on video at a southwestern Ohio air show and witnessed by thousands. The cause of the crash isn't yet known.
Jason Aguilera, the National Transportation Safety Board investigator leading the probe into the crash, said Sunday that it was too early to rule anything out and that the agency would issue its findings in six months to a year.
Wicker, a mother of two teenage boys and recently engaged, sat helplessly on the plane's wing as the aircraft suddenly turned and slammed into the ground, exploding on impact and stunning the crowd at the Vectren Air Show near Dayton.
The show closed shortly afterward but reopened Sunday with a moment of silence for the victims.
The crash drew attention to the rarefied profession of wing walking, which began in the 1920s.
The practice fell off the middle of the 20th century but picked back up again in the 1970s.
Still, there are only about a dozen wing walkers in the United States, said John Cudahy, president of the Leesburg, Va.-based International Council of Air Shows.
Teresa Stokes, of Houston, said she's been wing walking for the past 25 years and does several dozen shows every year. The job mostly requires being in shape to climb around the plane while battling winds, she said.
"It's like running a marathon in a hurricane," Stokes said. "When you're watching from the ground it looks pretty graceful, but up there, it's happening very fast and it's high energy and I'm really moving fast against hurricane-force winds."
John King, pilot and president of the Flying Circus Airshow, where Wicker trained, said the most important qualities of wing walkers are "strong nerves, a sense of adventure and a level head."