Dynamic Soaring Dissected

A description of how birds and aircraft fly, with particular reference to the dynamic soaring of albatrosses and the high-speed dynamic soaring of model gliders.

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Dynamic Soaring Dissected

Albatrosses fly over the oceans in swooping, curving flight gliding thousands of kilometres in search of food, mostly without flapping their wings. This is known as dynamic soaring, which is the use of the energy of the horizontal wind to sustain speed and height. It is different from the soaring flight of most other birds and gliders which use the vertical motion of the air to maintain or gain height. Since the 1880's, a time before manned gliding flight had been achieved, the mechanism of dynamic soaring has been poorly explained by the Rayleigh cycle or the wind gradient theory. However, there is more to dynamic soaring than the wind gradient and furthermore, the true nature of albatross flight has only recently been revealed by filming and GPS tracking. Dynamic Soaring Dissected takes up the discussion where it was left in the 19th century and explains how aircraft and birds fly. It looks at albatross flight through the lens of electronic tracking and takes us on a foraging trip with an albatross in long-distance soaring flight. In the Windward Turn Theory, it describes the mechanism of dynamic soaring and the hidden effect of the wind on a bird or an aircraft in flight. It explains the way that albatrosses are able to turn this effect to their advantage and how they are able to dynamic soar crosswind, upwind and downwind. It also describes how radio-control gliders can achieve huge speeds in circling flight and settles the perennial debate on the Myth of the Downwind Turn and what really happens when an aircraft turns downwind and ends up in a stall and spin accident.