Fly For 500 Meters While on Fire
Saints Row: Gat Out of SHOOTING STAR
The flying distance while on fire will be added up. A good spot for this are the lava streams on the right edge of the map. Fly directly through them and you will set yourself on fire for a short time. Land and repeat until you have 500 meters.
The more flying abilities you have the faster you will get the achievement / trophy because you will be able to stay in the air a lot longer.