I think we’ve unintentionally arrived at a complexity in the sim with the
calculation of the AMBIENT WIND VELOCITY simvar including all of the ‘world’
X, Y and Z wind components. For a long time, AFAIK, AMBIENT WIND VELOCITY has
been the goto simvar for the wind speed affecting the user aircraft and the
AMBIENT WIND Y (vertical wind) has been negligible. Now we have lift/sink in
the sim, AMBIENT WIND Y can have values considerably higher than the
horizontal wind speed, e.g. entering lift can have the AMBIENT WIND VELOCITY
change from 8 knots to 20+ knots. Existing devs could be forgiven for assuming
AMBIENT WIND VELOCITY and AMBIENT WIND DIRECTION are simply a matching pair of
simvars telling you the wind speed and direction (wind direction is unaffected
by the vertical wind, but the speed is significantly affected). An example of
the AMBIENT WIND VELOCITY simvar in gliding is displaying the wind on a
cockpit gauge, and also using the wind in a calculation of estimated arrival
heights. I can easily calculate a “WIND SPEED” var which will be the addition
of the X/Z wind vectors only, and use that in my internal calculations, but it
seems the kind of thing you’d expect the sim to provide, otherwise people are
going to continue to use the “AMBIENT WIND VELOCITY” as if it’s the horizontal
wind speed without realising how far it can be thrown off by the lift. My
suggestion is Asobo add a “WIND SPEED” simvar to the core sim as the majority
of sim developers simply use simvars rather than doing their own math to
generate core values.

Hello @B21 So you would expect the AMBIENT WIND VELOCITY simvar to only
represent the horizontal component of the wind? Is this based on a particular
standard or just what you think is the more practical in most case? Regards,

I think AMBIENT WIND VELOCITY is reasonably as current the magnitude of the
3-dimensional AMBIENT WIND X/Y/Z but the existence of that variable long
predates the arrival of strong lift (i.e. values for AMBIENT WIND Y) in the MS
Flight Simulator, and there is currently (AFAIK) no other simvar that just
gives you the strength of the prevailing ‘wind’ hence AMBIENT WIND VELOCITY
has been the de-facto simvar to use for that value. There are situations where
the (new) lift in MSFS considerably exceeds the prevailing ‘wind’ speed, so in
that circumstance the AMBIENT WIND VELOCITY can now be much higher than
conventional ‘wind speed’. For many applications you really just want the
'WIND SPEED" (wind sock angle, wind indicators in aircraft, long distance
glide slope estimates in glider nav instruments) so a wind simvar that
provides that would IMHO be useful, and some currently broken implementations
relying on AMBIENT WIND VELOCITY could be migrated in time to that new ‘wind’
simvar. It seems likely to me there are examples in Asobo code where AMBIENT
WIND VELOCITY has been used as if it reflects the current wind speed - e.g. it
might be where the wind speed is used in the lift calculation which
consequently has what I suspect is an unexpected positive feedback effect. If
we see similar quirky usage elsewhere in Asobo code it suggests a 2D wind
simvar would at least simplify code. I’ve created a general-purpose Z: simvar
in my model XML (Z:WIND_SPEED_MS) with an update loop which calculates the
vector magnitude of just the AMBIENT X and Z velocities, and for me that’s a
satisfactory replacement for AMBIENT WIND VELOCITY where I typically want the
2D wind not the 3D wind. It’s quite interesting to see how very different
those two values can become which is new in MSFS, and the usefulness of my
generic development suggests it’s equivalent in the core sim would make sense.

It is a little strange that the direction of the AMBIENT WIND VELOCITY vector
is not available, only a 2d direction (AMBIENT WIND DIRECTION). What about the