krasw wrote, On 5/17/2013 11:30 PM:
> On Saturday, 18 May 2013 02:33:22 UTC+3, Eric Greenwell wrote:
>> krasw wrote, On 5/17/2013 10:33 AM:
>>
>> I really curious about what an "accurate" speed-to-fly command is.
>> What
>>
>> is the command based on that makes it more accurate than the usual
>>
>> variometer, like a 302?
>
> Speed-to-fly is essentially function of vertical airmass movement.
> When you get inertial-based netto, which is very fast and accurate,
> your speed-of-command accuracy goes up order of magnitude. With
> normal TE-based speed-to-fly you normally try to filter out gusts
> with longer time constant. With inertial netto this gust-induced
> noise transforms into data that you can use for calculating optimum
> STF.
>
> With Butterfly I have actually started experimenting with extremely
> short time constant for inertial netto. It can be set so short that
> netto becames essentially a quantitative indicator of your
> seat-of-the-pants feeling. There seems to be no reason to filter or
> average this data so heavily.
Does it give the correct STF for 1 second from now? I can't possibly
change the speed of the glider that fast.
Or does it give me the STF for 10 seconds from now, which I might be
able to achieve with abrupt control movements?
And then, 10 seconds later, when I'm going the speed I was given, but
now I'm in air going down faster/slower, does it give me another STF
that will be wrong by the time I achieve that speed?
I'm trying get an idea of what you mean by "accurate" STF commands. The
top contest pilots I've followed seem to fly pretty steadily - will it
give me the STF that a top contest pilot will cruise at? That's what I
would call "accurate"!