Next weekend he will be in the Big Apple climbing stairs at 4 World Trade Center in another gut busting fundraising climb up 72 flights.
There are more than 340 firefighters from across the globe lining up for the 3rd Annual New York City Memorial Stair Climb.
There is a tactical plan when taking on stairs of Himalayan proportions.
"The secret is to have done the training. But the key is not to go out too fast and just pace yourself," he said.
"Your lungs are working really hard and it's about managing your air supply."
His training grounds have been a series of steps on the Waimahanga Track at Onerahi. And most of it has been done in the stifling summer heat. Seven times up the stairs is the equivalent to one burst up Sky Tower in Auckland.
Mr Powell was given a boost by local business The Drug Detection Agency (TDDA) which sponsored part of his travel expenses.
The other two volunteer firefighters from Northland heading to the US to compete are Andrew Ivey of Kamo and Darryl Trigg of Ruakaka.