Thoughts on the "caged birds in a plane" chestnut.

Danger

The 'thrust' of their wings is in addition to the lift that holds them up, and is transfered to the plane laterally through the air. The lift component is still equal to their weight.

Danger Recognitions: Gold Member	The 'thrust' of their wings is in addition to the lift that holds them up, and is transfered to the plane laterally through the air. The lift component is still equal to their weight.