Transcript for 'Wingwalkers,' 9, Land in Record Books
the two wing walkers we've been showing you. Two 9-year-olds. Rose powell and flame brewer, going to great lengths to raise awareness for muscular dystrophy, a disease that affects their close friend. Their flight is one for the record books. A abc's gio benitez has this remarkable story. Reporter: It's not something you see every day. Two planes, whizzing by, a few hundred feet above the ground. But take a closer look. What makes this absolutely incredible is that standing atop those planes are two 9-year-old girls. Now, the world's youngest wing walkers. And this, a flight for the record books. I'm getting really excited now. Reporter: The stunt was their idea to raise awareness for muscular dystrophy. And the pilot, none other than their grandfather. They're in special little seats up there. They're well strapped in with a five-point harness. I think they'll be fine. Reporter: Wing walking is not without serious risks, even for seasoned professionals. Just last year, jane whitford, the 44-year-old mother of two, died in a fiery crash, performing a routine maneuver at an air show in dayton, ohio. These girls were clearly having the time of their life. It was amazing. It was really cool. It was cool how you could see all the little houses. Weren't you terrified? No. I was a little at the takeoff. But once I was in the air, i just had loads of fun. Reporter: For "good morning america," gio benitez, abc news,
This transcript has been automatically generated and may not be 100% accurate.