Windtech zephyr User Manual

Page 11

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11

er paraglider and being 'waked' by the wing tip vortices of the glider and turbulence
wake turbulence of the pilot.

Remember, the pilot can learn to help stop collapses by flying 'actively', but if a front
tuck does occur it will easily clear itself. Re-inflating the wing can be helped by correct
pilot input and, once the glider is overhead, symmetrically applying 40 % of both brakes
and then releasing immediately will get pressure back in to the glider and speed up the
recovery. Do not brake when the glider is behind you, as this can stall the wing, but wait
for the glider to come forwards above your head, then brake.

-- asymmetric stall (spin)

This is a very difficult situation for the pilot to provoke with the ZEPHYR, given it's very low
stall speed, you have to really abuse the controls a lot to manage it. Even so, this situation
can be induced if, say, the pilot is turning very slowly in a thermal (near the stall point), and
wants to tighten the turn even more, and at the same time as smoothly lifting the outside
brake (which is the correct thing to do), if the pilot simultaneously brakes more on the inside
brake, this may stall the inside wing which will then go into spin. One half of the wing flies
forwards, whilst the other flies backwards (negative). In this case to return to normal flight,
one has to raise the inside brake, returning air speed to the inside wing, which will cause the
wing to surge and dive forwards. This dive can be more or less violent, depending on what
stage that the flat spin is in, how much the spin had been allowed to develop, and the
moment at which the brake is lifted. If the pilot wants to intervene to dampen this dive, they
will have to adopt a position (roughly) of something more than half brake, which must then
be released as soon as the dive is stopped, or the wing may then go back into a stall or spin.
Another option is to put the glider directly into a full stall immediately that the spin is
entered, and from this the exit is more symmetric with less chance of a twist.

-- landing

Choose a large field clear of all obstructions and in a clean laminar airflow.

A different technique is needed for different wind strengths. Every landing should be
judged differently even if it’s your local site.

On final approach the pilot should have hands up (keeping a feel of the wing in case of
unexpected turbulence) so the glider has energy for a flare. In light or nil winds the pilot
will need a committed symmetric flare at around 1 meter above the ground.

In stronger winds less of a flare is needed and the pilot must judge this for himself
through practice and training from a qualified instructor.

The flight is not finished, and the pilot is never fully safe, until the glider is safely con-
trolled on the ground.

Avoid letting the glider land on the leading edge. If the glider lands with force on the
leading edge it is possible to burst the inner cells and walls of the wing and you should
carefully examine the wing for any damage to the joining of the ribs to the cells.

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