On Jun 1, 9:52*am, John Cochrane
wrote:
On Jun 1, 11:44*am, Andy wrote:





On May 29, 9:22*am, John Cochrane
wrote:

Many people make the mistake of thinking wind affects final glide. It
does not (except for the above meteorological considerations). There
does come a point, gliding in to the wind, that lowering your
MacCready setting actually results in a worse glide. You'll see that
-- you get low, turn down the Mc, and all of a sudden you're even
lower! ouch!

I was involved in an animated discussion about this just last weekend
when a group of us was dining out after a fine day of soaring. *I was
assured that at least one popular glide computer does take wind into
account for final glide and that a setting MC=0 would always give the
best range glide solution for the known headwind or tailwind. *In
other words the glide computer is finding the MC setting that gives
max range (more than zero for a headwind and less that zero for a tail
wind) and displaying that as the zero MC setting. *I maintained that I
never had a glide computer that did that, but admitted it was possible
that someone had implemented it that way.

So designers, or users, of popular glider computers - Does your
instrument give max range at MC=0 regardless of wind or do you have to
adjust MC for the minimum vaue of required altitude?

That's a poor solution. A sticky knob that won't let you go below max
range would be better. If it shows Mc 0 but it's really set at (say)
Mc 2 because you're in a howling headwind, you need to know to cruise
at Mc 2 and not to take any 1.9 kt thermals. If the indicator shows Mc
0 you don't know that

John Cochrane- Hide quoted text -

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