In Point Break (1991), Patrick Swayze plays Bodhi, the leader of a group of surfers who rob banks to finance their surfing expeditions around the world, while Keanu Reeves plays Johnny Utah, a former star college quarterback-turned rookie FBI agent tasked with finding and arresting the robbers (called “the Ex-Presidents” because they wear rubber masks of former US presidents when they pull off the bank jobs). Utah learns how to surf in order to befriend Bodhi and his gang. Bodhi discovers Utah is an FBI agent and kidnaps his girlfriend Tyler Ann Endicott (Lori Petty) to force Utah into taking part in a bank robbery, and later forces him onto a getaway plane after a shootout at the airport.
Bodhi and another robber - who's dying from gunshot wounds - don parachutes and jump from the plane with the stolen cash. Utah doesn't have a parachute, but still jumps out of the plane in pursuit of the criminals. He lands on Bodhi and, after a game of chicken over pulling the cord to open the parachute, they land safely, but Utah reinjures his bad knee on the hard landing, which allows Bodhi to escape.
Did Reeves actually jump out of a plane without a parachute? Nope. Instead, director Kathryn Bigelow devised this memorable sequence by combining the following shots: (1) Swayze, who had real experience as a skydiver, jumped out of a plane backward while wearing a parachute; (2) Reeves's stunt double jumped out of the plane, supposedly without a parachute, although in this video for GQ that explains how the sequence worked, it's obvious the stuntman is wearing a rig under his shirt that can open into a parachute; and (3) closeups of both Reeves and Swayze plummeting through the sky. These last shots were filmed by suspending the actors from a crane that held them about 10 feet off the ground.
In It’s Make Or Break, a behind-the-scenes featurette about the film's production, Swayze described this rig, which had separate telescoping arms for both himself and Reeves that allowed them to move independently in and out of the shot:
They built a body thing with a post coming out of the center of it. We laid in that and you strapped yourself in and put your clothes on over it.
In the GQ video, Jeb Corliss, a professional skydiver, explained it was physically impossible for someone to manually hold onto another skydiver while in freefall. So it's probable that the two stunt skydivers were locked into each other's rig.
The producers used high-powered fans to simulate the wind, and also “floated” the cameras. According to second unit director/stunt coordinator Glenn R. Wilder, “…we had it so that we could turn and oscillate, and it worked out very well.” This allowed them to film Swayze and Reeves from the side or from below to create the illusion of skydiving.
As for the conversation between Reeves and Swayze once the former freefalls on top of the latter? Swayze said that wouldn't have been possible in reality:
You can’t talk in free fall. You’ve got 120 to 200 mile an hour winds, which is nothing but a giant roar. So there is a little bit of poetic license taken with us having conversations.