You must complete the Surface Skimmer, Entering Orbit and Take a Break! extras for this achievement.
Surface Skimmer – Keep the altitude warning for 60 seconds. Using any wings, gain a high speed and then fly close to the water and just travel along until it is completed. Having a high speed means that if you’re about to hit the water you can lift a little and carry on.
Entering Orbit – Hit 5km in altitude. You will complete this when travelling to Ascension.
Take a Break! - Fly continuously without landing or crashing for 12 minutes. As stated, fly around without landing on any platform or crashing for 12 minutes in total for these extras. You will probably get this when trying to collect all of the crystals, but if not head to Ascension and fly slowly downwards so that you will avoid crashing.