Slalom courses are typically found dotted across ski slopes around the world – nothing special there.
Take the gates and hang them from a helicopter thousands of feet in the air and things start to get a bit more interesting.
Then have top wingsuit pilots weave their way through this sky-high course, four at a time, at speeds of up to 257kph, and you have Red Bull Aces wingsuit race, which is returning for its second year on October 22–24.
Take a look at the awesome sky-high course here
The wingsuit pilots will run the course like skiers would take a slalom course, weaving their way in and out of gates – except these gates are between 1,828m and 1,066m high.
Wingsuit pilots navigate gates suspended in the sky
Four wingsuit pilots at a time will jump from a helicopter 2,300m above the ground, reaching speeds of 257kph. They will then be eliminated in rounds, leaving the fastest as the winner.
Four jump and then race at a time
The race takes place at an undisclosed location in Northern California after its first staging happened in Oakdale, California, in 2014.
See some highlights from the 2014 race here
This year 40 wingsuit pilots from 19 nations will compete in the tough race.