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How does the glider stay in the air if it has no prop? |
This is a very valid question. The concept of soaring or gliding was
actually borrowed from the eagle and other large birds. Gliding depends a lot on what we call thermals.
Thermals are areas or columns of upward moving air. Thermals are
normally found where clouds are formed, and can also be seen on the
ground if they form a dust devil. Dust devils, or dusties, as we call
them, are at the bottom of the thermal. Thermals are stronger in
the core, and when an eagle rides a thermal, he will search for the
part that will give him the most lift in the shortest time. This is
exactly what we do with gliding. In other forms of aviation, thermals
can be an irretation, because if you fly through it, the ride is bumpy.
For gliding pilots, that is a good sign. If the left wing lifts, you
know that the thermal is to your left, or if the right wing lifts, it
is to your right. The pilot then begins to circle the glider in that
direction, until he finds the core of the thermal. The idea is to ride
the thermal until it dies out, or until he is high enough to fly
further. Some high performance gliders have a gliding ratio of 60:1. The implication
thereof is: If a pilot could take a thermal up to 10 000 ft, he would
be able to glide 600 000 ft horizontally in optimal conditions. Thus
for every foot of hight, he can fly 60 feet horizontally loosing only one foot. Initially,
thermallig may look like a form of black magic, but with practise you
will be soaring with the eagles in no time! The better you can thermal,
the better you can fly.
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