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Old 02-15-2010 | 10:34 PM
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ryan1234
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From: USAF
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Originally Posted by oldveedubs
L/Dmax is not a function or weight, wind, or airspeed....it is a function of aerofoil. If the aerofoil isn't changing, drag polar stays the same.

That being said, wind will change your "speed to fly" based off how a tangent line intersects with the polar.

In very basic terms, you add 1/2 the headwind to your L/Dmax speed and subtract 1/4 tailwind...this is known as your speed to fly, talk to some glider pilots.
(L/D)max, won't be affected by wind. If all other factors (i.e. airspeed, etc) remain constant, any one factor (i.e. weight) increase/decrease will make the L/D shift.

The point being though that sometimes (L/D)max does not equate to the best glide speed for range if you're in a headwind or tailwind.... which is why glider pilot increase/decrease their airspeed like you said.
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