Transcript for Extreme Stuntman Called 'Flying Dagger' Stunt 'Absolutely Terrifying'
In this the go pro generation, there are plenty of dudes willing to jump out of the sky just to post their exploits on the web. But few take as many or varied risks as jeb coreliss from the eiffel tower to empire state building if it is tall and famous he has jumped from it or been arrested trying. For his latest stunt this bold and/or cuckoo young man took his wing suit and gloria rivera went along. Reporter: Take a look at this, the view from 4,000 feet. Shot by extreme stuntman jeff coreliss flying at terminal velocity. A van wing suit pilot, he has swooped through waterfalls, around the christ the redeemer statue in rio, and over swiss mountain tops. Soaring with his manmade wings. But now he is about to attempt the impossible. When weep were up there, the wind is super strong. Reporter: We joined the team who cam to eastern china to try a stunt so daring, complex, so well insane really he couldn't resist it. Though he nearly didn't live to see it. What I wanted to do since i was a small child is fly. I looked up at the sky since i was young. I watched bird fly. I thought, man. Wouldn't that, that its just -- who wouldn't want to do that? You know what I mean? Jeb is not alone. There is a formula one in the sky. Coreliss arguably the sport's top gun. In january 2012. Three, two, one. Reporter: Training on table mountain in south africa, flying over sheer granite at 120 miles per hour, a near fatal crash. Dude, I didn't think I was dead. I knew I was dead. There is, you do not hit at terminal velocity and survive. It is impossible. Not even two years later -- need to stop traffic. Reporter: Fully recovered, jeb preps the team to pull off the latest stunt. Heave calls it "the flying dagger." His goal to fly between the jutting blade of the cliffs aiming for the narrow gap. One wrong move, all but certain death. Bizarre geologice lological anomaly. Three football field long. 900 feet tall. Unlook anything I have seen. Reporter: To get a since of what he has to do we take a hike. We are in it. From where I am, it can't be more than 16 feet across. This is what jeb has to fly through. Anything goes wrong. This could be it. This is absolutely terrifying. Reporter: It might shock you to learn that jeb, a guy who skirts death for a living is terrified most of the time. If this doesn't scare you, i don't know what does. Reporter: Jeb has three days to pull the stunt off. This kind of feels like meeting someone who made a deal with the devil. There its nothing between here and there. Reporter: It seems the devil is behind the bad weather. I would say it is gusting up to 15 at times. Starting to right now. Not safe to land. Talk to me what you are seeing here? We were supposed to start practice jumping yesterday. And, yesterday, the winds were really bad. And then the cloud ak sthactually covering the mountain. Reporter: Not ideal. As not ideal as the it gets. Reporter: Jeb gets word and gets ready. A break in the weather. The wind calm for the first time. The plan tips getis to get as many practice jumps above the crevice as possible before he flies through it on the big day. For months jeb has been training with high-tech help. Simulating the exit from the chopper. How to fly through a crack, 15 feet wide at points. 900 feet tall. Three football fields long. And how to land on a narrow mountain edge. One thing to do the stunt. Another to land safely. Whoa! Reporter: Oh, my god. The first practice landing is hard. But jeb's pumped. Nice. Ha-ha-ha. When I saw it. It was very exciting. It really was. Although very scary. As long as you stay in the center you are all good. So we get good wind, dude, I am telling you right now this will be the most epic stunt I have ever done. Reporter: Hey, guys. Hello. Reporter: Stunt day, bad wind is the one thing he can't control. Reporter: What's up? Bad weather is up. Lot's welcome the adventurer to the stage. Reporter: Jeb's press conference he is losing faith that the stunt will happen at all. Millions in china alone will be watching the live show. But with the clock ticking the weather goes from bad to worse. This is the worst day we have seen so far since we got here. It happens. I mean -- in the end, i, I -- i just don't like disappointing other people. Reporter: Ideally wind would be zero. Today they're 10 plus. Chinese authorities say it has the to be now. This its such a sketchy, sketchy, sketchy thing right now. Yeah. I don't like it when it is like, yes/no, yes/no, yes/no. Everything is frustrating. Reporter: Despite conditions jeb decide to go foirr it. With the wind suddenly calm it is a go. In just five seconds -- at 122 miles per hour -- jeb becomes the first person ever to pull off the flying dagger. Yeah! Reporter: And a pinpoint landing hitting right where he wanted to be if not quite on his feet. Minutes later he tells us what went through his mind. The fear gripped me hard. All of a sudden I started getting really scared. Then it became so overwhelming i started crying. I am look dude this is wrong. This is dad. Something bad is going to happen. I was really gripping with the fear. All of a sudden as I came in i came that close to the wall. The feeling was so unbelieve be powerful. There really are not word to describe. Reporter: Jeb says he is not a daredevil. Hates being afraid. But loves what it feels look to push through the fear. Today he has done it. For "nightline," gloria rivera in china.
This transcript has been automatically generated and may not be 100% accurate.