On Oct 3, 7:54*pm, Eric Greenwell wrote:

If wind is important to you, spend the money for an air-data instrument.

Even the best on board measuring system can only tell you what the
wind is here and now, and what it was where and when.

No on-board measuring system can tell you what the wind will be
someplace you have not been yet at some time in the future, and that
is what we need for those long final glides and presumably for long
ridge flights and ridge transitions.

Flight management systems allow the entry of wind forecasts at
multiple altitudes for the various en-route waypoints. Perhaps a smart
glider flight computer would allow entry of discrete point wind
forecast data, or even derive them automatically from a web source.
Perhaps a smarter one would enable the wind forecast data to be
updated in flight. For example local winds at different altitudes
could be derived from FLARM transmissions from other gliders in the
area.

One problem with dreaming of systems like this is that in-flight
reception of weather data, other than by voice radio, is prohibited by
US contest rules. It's OK to listen to an AWOS or ATIS but not OK to
receive the same data from, for example, XM weather.

In the past looking outside has provided very useful indicators of
wind strength and direction. I see no reason to assume that source
will go away as technology advances.

Andy