Stalling - Advance Sigma 7 Betriebshandbuch

Caution: The SIGMA 7 is certifi ed for harnesses in group GH
(without rigid cross-bracing). Group GX harnesses (with
cross-bracing) or those with very low hang points could dras-
tically alter the fl ying behaviour in the spiral dive. See section
«Suitable harnesses».
Caution: Do not fl y spiral dives or aggressive changes of
direction with big ears applied: the raised wing loading carri-
ed by fewer lines can damage the glider.
B or C Stall
The B or C Stall puts extremely high stresses on the material and the
profi le shape of the glider. We recommend that you do not do B or C
stalls (although these manoeuvres do not present special diffi culties
to the SIGMA 7).

Stalling

One-sided stall (spin)
In a tight turn the SIGMA 7 gives you early and clear warning of the
risk of airfl ow breakaway by a strongly increasing brake load. If, how-
ever, the wing does stall, the SIGMA 7 will react dynamically. Depen-
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ding on the situation in which you allow the glider to fl y again a violent
response may result (shooting forward with a heightened risk of col-
lapse). The canopy can be stabilised with coordinated brake action
as it shoots forward. Normal fl ight can then be re-established without
causing further collapsing.
Tip: Basically you should immediately release both brakes
completely in all out-of-control fl ight situations, but especially
at the onset of spinning behaviour.
Full stall
Entry to the full stall is achieved by progressive symmetrical applica-
tion of both brakes. This action reduces the forward speed. Airspeed
and wind noise reduce. After reaching minimum speed the glider go-
es into a brief phase of deep stall. Further application of brake causes
the airfl ow to completely break away from the wing, and the glider will
fall back in full stall.
To recover, the canopy must be pre-infl ated over its entire span. To
do this the brakes must fi rst be slowly released and then fully re-
leased when the wing is completely infl ated.
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04.06.2008 14:27:51 Uhr 04.06.2008 14:27:51 Uhr