Complete the following tasks to unlock Apple Game Center achievements.

Achievement	How to unlock
Centurion	Reach 100 Total Aircraft Landed.
Crowded Sky	Reach 20 'Most Aircraft on Screen'.
First Flights	Land an aircraft on each airfield.
Helicopter Love	Land 5 helicopters in a row.
Holding Pattern	Keep the same aircraft in the sky for 5 minutes.
Jet Power	Land 20 jets in a game.
Perfect Timing	Land 3 aircraft at the same time.
Restrainer	Land no aircraft for 2 minutes.
Rush Hour	Land 7 aircraft within 12 seconds.
Safety Card	Read the game tutorial.
Veteran	Play 250 games in total.
Wings	Land 200 aircraft in a game.