He said he had to get himself into a certain mentality when attempting the jump and was solely focused on it while in the air.
"I get into almost this meditative state when doing those sorts of things [backflips]. I count the rotations and keep an eye out for the landing spot," Mildon said.
"With the quadruple, I was going 'snap, tuck, lock, okay that's it. Spin, spin, spin, there's the landing. Okay, open out and land'.
"I'm not really thinking about what I'm going to have for dinner or anything. Just getting the trick done and then calling mum to tell her I landed it!"
A one-hour long documentary which focuses on the quest to land the first quadruple backflip will screen on TVNZ Duke this Sunday after getting run time on NBC in the United States.
Revolution Day will be on the air at 5pm.
With a sport requiring the precision that BMX does, injuries are part and parcel. However, Mildon said he had been relatively well off in that domain.
"I've been reasonably lucky but I think the main injury you need to watch out for is concussion. Your brain cells are pretty important. Bones heal, ligaments heal - it's just a matter of time," he said.
"But you can't just bounce back from a head knock so I recommend everyone wears a helmet."I've ridden with broken toes; I did 37 shows with a torn supraspinatus which is a ligament in your shoulder."I rode for nine months with a broken T5 and T7 vertebrae in my spine. I must have a high pain threshold. I don't recommend you live like that; it's just that it didn't hurt."
Mildon doesn't just attempt the crazy jumps he does; he makes the ramps. Throughout his successes, he's been able to strike up a friendship with a legend of the art: Travis Pastrana.
"Once I gained the knowledge and desire to build ramps and design them myself I did it. I built my ramps for my double flip and my triple flip," he said.
"The ramp I used to do the quadruple was built by the best ramp builder in the world, Nate Wessel, at Travis Pastrana's house. Other than that trick and the show ramps, it's all me."
"Every time I see Travis I don't know what to say. I've been his friend for six years now and I'm still like a fan-boy. He makes things comfortable for you."He's a legend in all our eyes and will never not be a legend to us. I still look up to him now, as does everyone on the circuit."
Mildon said the crew were excited for the second stop on their 68-show tour.
"For this event, I've been working on a few new tricks. It's going to be our second show out of 68 so it's going to be great," he said.
"We haven't toured since October 2015 so the boys will be raring to go so the Whangarei event will be epic."
Next Sunday's Nitro Circus stop will provide thrills and potentially spills as the athletes attempt things that most wouldn't dream of.
But that doesn't stop Mildon continuing to get better for fans of the sport.
"I learnt a bunch of a new tricks before the tour but I've basically honed in on tricks that I know I can perform for the tour. Some of the tricks I do are really scary and I still lose sleep over."But that's why it's the best action sports show in the world because we push it as far as we can. We go to the heights that we do and the spins that we do for the people."