In terrifying footage caught on a skydiver's helmet camera, Christopher Jones can be seen having a seizure mid-air, his convulsing body tumbling to the ground until his partner is able to trigger his parachute.

Jones, 22, the Sydney Morning Herald reports, was performing a 3,600-meter (or about 12,000 feet) jump above Western Australia as part of the advanced stages of a training program when he suffered a seizure. (He had previously been cleared by his doctor to skydive.)

"At around 9000ft I have a seizure while attempting a left hand turn," Jones writes in the video's description. "I then spend the next 30 seconds in free fall unconscious."

At about the 1:15 mark in the two minute clip, you can see Jones seizing up and free-falling. Sheldon McFarlane, his instructor, was able to pull Jones' parachute before he hits the ground, though he also told the Guardian that had he not reached Jones, an emergency device would have automatically pulled his cord.

McFarlane's save occurred last November, but according to the Guardian, Jones didn't get around to uploading the video to YouTube until this past weekend.

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