Deep Stall / Parachutal Stall - Ozone Viper 2 Betriebs-Handbuch

INCIDENTS

Deep Stall / Parachutal Stall

It is possible for gliders to resume their normal shape on a very
slow release of the B-lines, but carry on descending vertically and
without full forward motion. This situation is called 'deep stall' or
'parachutal stall'.
It is unlikely to happen on any OZONE glider, but should it hap-
pen, your first reaction should be to fully raise both brakes and the
glider should return to normal flight. If nothing happens after a
few seconds, reach up and push the A-risers forwards or apply the
speed bar to regain normal flight.
Ensure the glider has returned to normal flight (check your air-
speed) before you use the brakes again.
IMPORTANT: Only a few cms of input from your brakes can
maintain your wing in the stall. Always release your wraps
if you have taken them!
Deflations
Due to the flexible form of a paraglider, turbulence may cause a
portion of the wing suddenly to collapse. This can be anything from
a small 30% (asymmetric) collapse to a complete (symmetric) col-
lapse.
If you have a collapse, the first thing to do is to control your direc-
tion. You should fly away from the ground or obstacles and other
pilots, or at least not to fly into them... Asymmetric collapses can
be controlled by weight shifting away from the collapse and apply-
ing a small amount of brake to control your direction. This act will
most of the time be enough for a full recovery of the wing
.
Once a glider is deflated it is effectively a smaller wing, so the wing
loading and stall speed are higher. This means the glider will spin
or stall with less brake input than normal. In your efforts to stop
the glider turning towards the collapsed side of the wing you must
be very careful not to stall the side of the wing that is still flying.
If you are unable to stop the glider turning without exceeding the
stall point then allow the glider to turn whilst you reinflate the col-
lapse.
If you do have a deflation, which does not spontaneously reinflate,
make a long smooth progressive pump on the deflated side. This
pumping action should take about 2 seconds per pump. Pumping
too short and fast will not reinflate the wing and pumping too slow
might take the glider close to, or beyond, the stall point.
Symmetrical collapses reinflate without pilot input, however 15 to
20cm of brake applied symmetrically will speed the process. If you
simulate a symmetrical collapse during an SIV course it is impor-
tant to use both the A and Baby A risers and to pull evenly to in-
duce a symmetrical collapse. Use of just A risers or uneven pulling
may lead to the glider collapsing only in the centre section with the
tips flying forward to meet in the middle, leading to an increased
risk of a cravat occurring.
If your Viper 2 collapses in accelerated flight, immediately release
the accelerator to slow down to trim speed and after a 90 deg turn
the canopy will reinflate and return to normal flight.
Cravats
When the tip of your wing gets stuck in the lines, this is called a
'cravat'. This can make your glider go into a spiral, which is difficult
to control. The first solution to get out of this situation is to stabi-
lize the glider into normal flight by maintaining control of your di-
rection and then pull down the stabilo line (red line on the B-riser)
until you feel tension to help release the tip. You must be careful
with any brake inputs or you may stall the opposite wing.
If this does not work, a full stall is another option. This should not
be done unless you have been taught how to do so and it can only
be done with a safe amount of altitude. Remember if the rotation is
accelerating and you are unable to control it, you should use your
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