Advance acoustic SIGMA 9, Руководство пользователя

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Speed system with SPI
The SIGMA 9 has a speed system with a Speed-Performance-
Indicator (SPI), which reads off against 3 positions on the backs of
the risers . The red markers on the speed system enable a precise
speed bar position to be set to suit the in-flight situation .
Best gliding to the next thermal needs an on-going choice of
speed to fly, depending on the current values of headwind, expec-
ted next climb rate, and the rate of sink .
Thanks to its high stability the SIGMA 9 can be flown in accelerated
condition in light turbulence without problem . The choice of ac-
celerated speed for best glide does play an important role for this
high performance glider .
Each of the SIGMA 9 SPI positions has an icon with a value for
headwind, expected climb and sink rate . These indicated positions
are effective for only one of their three values, taken in isolation –
considered by itself . This means that either the headwind, or the
expected rate of climb, or the sink rate applies to that position . The
SPI principle is based on the simple (using headwind and sink) and
the extended (including expected climb rate) McReady Speed-To-
Fly theory .
Example SIGMA 9 / 25
Position neutral
Position 30%
Position 80%
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