How do they quickly replace the pylons after a hit during the Red Bull Air Races?
The 25m tall asymmetrical pylons used in Red bull air races are made of 9 different sections, which are connected with zippers for easy removal and installation. In this image, you can see the multiple sections that make up the pylon.



Interior of redbull air race pylons; image from redbull air race

Airgators Team Captain, Holger Leprich, who is responsible for replacing the pylons after a hit, explains the procedure in this video.


The pylons are held up using air pressure- electronically controlled equipment at the bottom of the pylon creates a positive air pressure so that the pylon stands upright.
For each competition, there are three five member pylon replacement teams (called Airgators) to ensure quick replacement- their current record being 67 sec.
The pylon is designed to tear off in case of a hit. Once the pylon is hit, the team moves to the damaged pylons location on clearance from the race director.
Once the team reaches there, a couple of guys control the electronic equipment (and deflate the pylon, if required) at the bottom of the pylon, while another two replace the damaged parts- they simply unzip the damaged part and zip in the new one, while the last one checks the pylon.
Once the replacement is completed, the team inflates the pylon. Mission accomplished.