10
Spiral Dives
If you turn your Geo in a series of tightening 360's it will enter a
spiral dive. This will result in rapid height loss.
To initiate a spiral, look and lean in to the direction you want to go,
then smoothly pull down on the inside brake. The GEO will first turn
almost 360 degrees before it drops in to the spiral. Once in the spiral
you must apply a little outside brake to keep the outer wing tip
pressured and inflated.
Safe descent rates of 8 metres per second (500 ft/min approx.) are
possible in a spiral dive, but these high speeds and G-forces can be
disorientating, so pay particular attention to your altitude.
To exit the spiral dive, slowly release the inside brake and apply a
small amount of outside brake. As the Geo decelerates allow it to
continue to turn until enough energy is lost for it to return to level
flight without an excessive climb and surge.
IMPORTANT : Spiral dives with sink rates over 8 m/s are
possible, but should be avoided. They are dangerous and put
unnecessary strain on the glider.
Spiral dives cause disorientation and need time and height to
recover. Do not perform this manoeuvre near the ground.
Neutrality in Spiral Dives
We call a glider neutral in spiral dives when it stays in the spiral
despite the fact that you have put your hands up. To stop it the pilot
have to counter steer on the other side. A glider which is instable in
spiral dives will accelerate into the dive without input.
The GEO which is certified DHV1-2 is neither neutral nor instable in
spiral dive. However some parameters could interfere with its
behaviour : wrong settings of the chest strap, total weight in flight
outside of the weight range, or being in a very deep spiral at a very
high sink rate, you should always be prepared to pilot the wing out
of a spiral dive.
Incidents
Deep Stall / Parachutal stall
It is possible for gliders to resume their normal shape on 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 highly unlikely to happen on any OZONE glider, but should it
happen, reach up and push the A-risers forwards until normal flight
returns. Only then should 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.
If you have a collapse, the first thing to do is to control your
direction: You should fly away from the ground or other pilots or at
least not fly into them...
Asymmetrical collapses can be controlled by weight shifting away
from the collapse and applying a small amount of brake to control
your direction.
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
collapse.
To reinflate a collapse, make a long, smooth progressive pump on the
deflated side. This pumping action should take about 2 seconds per
pump. Pumping too fast won't reinflate the wing and pumping too
slow might take the glider too close, 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 important
to use both the A and Baby A risers and to pull evenly to induce 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
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