Traveling at speeds of up to 386 kilometers per hour, 164 skydivers flying head-down connected with each other to form the largest ever vertical skydiving formation on Friday over central Illinois, smashing the previous record.

It took the international team 13 attempts to beat the 2012 mark set by 138 skydivers. The formation, resembling a giant flower, floated above the rural drop zone in Ottawa for a few seconds before the flyers broke away, deployed their parachutes, and whooped and hollered their way to the ground to the jubilation of spectators.

"It's awesome, man," said Rook Nelson, one of the organizers. "It just goes to show that if you can get the right group of people together and the right support team and good conditions, anything is possible ... even on attempt No 13."

The team was selected after training camps in Spain, Australia and across the US. Seven aircraft were flown in precise formation to ensure that the jumpers exited the plane at the right place, time and altitude.

Skydiving videographers taped the jump, flying above, below and alongside the formation. The footage enabled judges on the ground to verify the record was achieved above Skydive Chicago, the airport drop zone about 80 miles southwest of Chicago.

Three judges certified by the World Air Sports Federation studied the video and photos to make sure each jumper was in a predetermined slot in the formation and had his or her hand in the correct position.

The record was not without risks. The skydivers flew at a minimum speed of 257 km/h, and some reached speeds as fast as 386 km/h. A collision at such speeds can be fatal.

Jumping from such a high altitude brings a risk of hypoxia, a condition arising from a lack of oxygen that can cause unconsciousness and other symptoms, or even death. To reduce the risk of sickness, jumpers and pilots inhaled pure oxygen once the planes reached 14,000 feet.

And with nearly 170 canopies simultaneously flying in the sky, there's a risk of two parachutists flying into each other.

Still, of approximately 3.2 million sport skydives in the US in 2014, there were 24 fatalities, according to the United States Parachute Association.

Despite the risks, participants came from as far away as France, Britain, Dubai and Australia. One even spent three days traveling to Chicago from Reunion, off the coast of Madagascar in the Indian Ocean.

"When jumps work well, it's like there's a certain peace to it all, a certain harmony to it all," said Norman Kent, a longtime skydiving videographer who filmed the jump. "And it's contagious; it's like it's in the air and you can feel it even from a distance as a cameraman."