Snowball's Chance can be found in the "Last Chance" area in the northeast.
Sinterpol HQ can be found in "Rebellion Square" towards the southwest, near the highway.
I highly recommend you have ALL the Flight Upgrades, although they aren't 100% necessary, they do help a lot. You will need a good amount of stamina and at least 3 flaps to get there without major problems.
Now go to Snowball's Chance Hotel & Casino, and make your way to the roof of the tallest part. Use your map to mark the location of Sinterpol HQ. Charge your jump, and begin sprinting in a circle until maximum speed and then jump out towards the middle of the map. At the peak of your jump, begin flying. I recommend 1 flap pretty early, another soon after, and your 3rd and final flap as you pass the large floating building that you pass at about the halfway mark. Maneuver your way around the building towards the marked building. I recommend that you fly directly over it and then use "Flight - Hover" above it to get the achievement/trophy to unlock, although hitting the the very peak of it will also work. If you miss the peak, it will most likely not work.Note:
From personal experience, it will not work if you dodge spire missiles along the way.