Watch BASE Jumpers Make Death-Defying Descent Into Moving Airplane

French wingsuit flyers were seen attempting a lofty stunt involving two moving airplanes after the two had BASE jumped from the Jungfrau mountain in Switzerland. The two-minute and 22-second video of the stunt, which was posted on YouTube by Red Bull, went viral and has been viewed over 15,000 times as of Tuesday.

BASE-jumping experts Fred Fugen and Vince Reffet, known as the Red Bull Soul Flyers, jumped out of a moving airplane into the cabin of another plane as it soared over the Swiss Alps.

Red Bull sponsored the stunt. The duo trained for months and did not use a parachute, according to the site.

"We wanted to celebrate the 20th anniversary of Patrick de Gayardon's achievement in 1997, when he jumped from an aircraft with a wingsuit and then flew back into the plane," Reffet said. "He was a pioneer in our scene and we wanted to reproduce his stunt. At the beginning of the year, I woke up one day and said to Fred, We have to do it but with a BASE jump from a cliff!"

Fugen and Reffet have been BASE jumping for years. But this stunt was different since it required more focus as they tried to land inside of the plane’s cabin instead of free-falling.

"It's cool but also quite weird! We're used to jumping from the plane, but here you have to enter into it," Reffet said. "You're falling down and all of a sudden there’s no air anymore. The feeling is quite strange. When you're in the plane and you see your friend flying closer and closer, it's incredible. It was very emotional for us because we worked hard to make it happen."

BASE jumping is an acronym for the type of objects the jumpers might propel themselves from, such as buildings, antennas, spans and the Earth. BASE jumpers usually wear a parachute and a wingsuit, which allows safe travel through the sky.