Ground effect would be of little use to me

because I wouldn’t have the speed to enjoy its

benefits and I wasn’t going to be able to vary

the way I flapped my wings, so I would just

have to rely on good old pedal power!

In order to achieve thrust and lift, I was going

to have to pedal like the clappers, but birds do

it simply by flapping their wings. Yet the wing

flap is not as simple as it looks. A bird’s wing

generates lift in exactly the same way as an

aircraft wing, using the difference in pressure

created by air flowing over and under the

wing. Small birds jump or hop forwards to

generate the initial airflow while larger

birds run into the wind.

Once airborne, a bird’s wings also turn into

its propellers when the bird flaps. Different

areas of the wing have different jobs to do.

The part closest to the body moves least and

provides basic lift, but when the bird flaps its

wings downwards it is also pushing part of the

wing forwards, tilted at an angle. This changes

the airflow over that part of the wing so that

the ‘lift’ is in a forward direction rather than

straight up. This is actually what our propeller

is doing when I described it earlier as being

like ‘a slightly twisted wing’. The feathers on

the wing, meanwhile, are performing all sorts

of other important tasks.

NATURAL BORN FLYERS    117