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A thermal
generally tries to push a soaring aircraft or bird away from its core where the lift is best. Thus,
the pilot has to work constantly to keep the glider centered within the thermal for the best chance of gaining
altitude. The lower the altitude, generally the harder it is to "core" a thermal, so you’ll have to concentrate
and pay close attention to the signals your glider is giving you as it responds to the quickly changing
dynamics of a growing thermal. A sign that a thermal might be very close is if you notice your glider
suddenly being pushed or turned away from its current path. If one of your wings should rise noticeably, the
common technique is to turn towards that wing and into what is hopefully rising air (this is not always true
since turbulence can also cause the glider to alter course). So, you’ll most likely have to make constant control
corrections to force your way into the thermal's core, since the thermal will do its best to spit you out into the
surrounding sinking air that feeds the thermal. Typically, a glider will speed up slightly in lift and slow down
and wallow in sink (downward moving air). If the glider speeds up a bit in level flight and doesn't seem to
be losing altitude, start circling and use your elevator to slow the glider down and gain altitude.
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Location and time of day
is very important when it comes to flatland soaring with small, lightweight, hand-
launched gliders. Usually, the best time is middle to late morning before the wind starts to pick up too much.
As the wind increases in the afternoon, it becomes more difficult to navigate thermal lift as conditions get
“blown out.” Keep your eyes peeled for soaring birds. They will always find the best lift! Just because a
location looks good does not mean you will find good updrafts there. Local wind patterns and topography
have a large influence on the "soarability" of locations and may cause a great-looking field to have
turbulent and/or sinking air currents.
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