How do you earn Free Gems?

To have any chance of winning tournaments you will need to earn gems so you can spend them on boosts. Completing quests will allow you to get those gems for free. You can also place planes onto the track and just let them race around endlessly for awhile. Make sure you do this with your higher level planes as they will earn you considerably more coins than if you use lower-level planes. When you know that you are going to be away from the game for an extended period make sure you track is loaded with planes.

The other way to get gems is to use real money and purchase different quantities of gems from the App Store. Also available at the App Store is the Gold Membership which will give you 10 gems each day as well as faster speed, more fairways and parking spaces and a 120% offline earnings multiplier.