For this trophy you dont have to fly the entire 500m in one go.....with enough, or none, resistance upgrades, go down into the depths of hell where the lava ocean is (on edges of map also works) you will notice a constant spew of burning liquid. Fly up and down couple of times going through this burst of lava, flap your wings to give that boost of speed. After every 100m you do, a notification will pop. Goodluck.