Windtech serak - Manual (Page 13)

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shift less hard, to regain level flight. Like this, the pilot can control the bank angle and
the sink rate of the glider in the Spiral dive. Always remember that whilst in the Spiral
dive you are drifting with the wind, and it is very easy to become disorientated.
This manoeuvre is not approved for bank angles higher than 60 degrees. At this upper
limit the sink rate of the canopy is approximately 10 m/s and the overload is equal to
2G's.
For bank angles higher than 60 degrees the sink rate can achieve 20 m/s but the greater
overload (G's) can cause eyesight and equilibrium problems, and cause some people to
'black out' (faint), which consequently can make the manoeuvre extremely dangerous.
To recover from a spiral dive, the inner brake must be progressively and slowly released,
until the canopy assumes normal flight, and angle of bank, again. A good rule of thumb
is to use the same number of 360-degree turns as you did on entry on exit to give a safe
and progressive pullout. If you release hands up from a tight spiral dive you will expe-
rience a big surge followed by a dive. (In turbulent air this can result in a collapse.) The
S E R A K has been tested for this but it is advisable to learn the correct exit method, i.e.
progressively release the inside brake.
> b stall
The B-line stall is a real stall, and even though the wing appears to be flying above your
head the laminar airflow over the wing is completely lost. During B-Stall, the canopy
falls perpendicularly to the ground (straight down, but drifting with the wind) at a sink
rate of 5 to 12 m/s, with an angle of attack of 90 degrees.
To enter a B-Stall, it is necessary to sit upright in your harness, reach up with the brakes
still in your hands (preferably with the toggles around your wrists) & securely clutch each
B risers in each hand at the top near the Maillons Rapides (quick links). To enter the B-
line stall, pull down symmetrically on the B risers. (About 40 cm)
The force initially is quite hard (up to about 15cm) but for the last part the force requi-
red to pull down is less. Keep your weight centred in the harness, and keep the risers held
at a symmetric level to each other. The more B riser pulled the faster the decent rate, but
the glider can become unstable with a very deep B-line.
To return the glider to normal flight conditions:
Ease up the B-risers SYMMETRICALLY for 50% (25-cm of B-line still held) holding some
pressure, then symmetrically completely and rapidly release them. What you are trying
to achieve is to not shock-load the glider by an immediate release from a deep B-line,
whilst at the time not easing off too slowly and risking a deep stall in turbulent condi-
tions.
Releasing the B-lines from a deep B-line position works fine (& if unsure whilst attemp-
ting the manoeuvre simply release the B-lines together from this position) but puts
unnecessary load on the glider.