How do birds fly? – Space Zone

Question: How do birds fly?
- Keywords:
  bird,
  fly
Asked by maeve99 to Arlene, Colin, David, Eugene, Paul on 18 Nov 2012.
- David McKeown answered on 18 Nov 2012:
  
  There wings help them glide like a hang glider, when they run out of speed they have to flap their wings to generate lift and thrust to propel them forward. Their feathers trap the air making this possible, they also have big chest muscles to power their wings and light, but strong, hollow bones.

Question: How do birds fly?