There are to many reasons that you can fly than can be mentioned here.  The important thing is you can.

You may carry objects/people as long as your strength allows you to lift it, and you spend stones to counter its weight.  These stones do not count toward airspeed.  Buying the proper Ability Bonus can help you carry more while still traveling at top speed.

Rules for Action Box:

• Flight speed up to AN

• Add stones for extra weight