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61
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EN
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60
C-line stall
This manoeuvre is occasionally recommended as a descent technique.
It is instigated by symmetrically pulling the C-risers. The wing loses its
forward momentum and begins to descend. This manoeuvre is basi-
cally possible, but should only be practised with a qualified instructor.
Collapses
Asymmetric collapses
When flying into strong turbulence, one side of the paraglider may
collapse. This happens because the turbulence causes the angle of
attack on that side to decrease to the extent that lift is no longer
generated, the lines de-pressure and the wing collapses.
Such a collapse normally only affects a small part of the whole span and
the wing will not react significantly. During larger collapses which affect
50 percent or more of the span, the wing will clearly react:
due to the increased drag of the collapsed side, the glider will begin to
turn towards that side. Simultaneously the wing will pitch forward becau-
se of the reduced area carrying the wing loading, i.e. because this causes
that side of the wing to accelerate. The pilot can prevent this turn and
forward pitch by braking the uncollapsed side of the wing. Braking the
uncollapsed side is essential, especially near the ground. This manoeuvre
should be practised with induced collapsed at height, preferably during
an SIV/pilotage course.
Frontal collapse
A frontal collapse is also a consequence of turbulence. Unlike an asym-
metric collapse, during a frontal collapse the whole leading edge folds
downwards.
All our paragliders open automatically after frontal, as well as asymme-
tric collapses (as stipulated in the certification standards). To speed up
the re-inflation of the leading edge after a frontal collapse, we recom-
mend a very short pull of both brakes. It is important to then release
both brakes completely.
During frontal collapses induced through the A-risers it is difficult to
collapse the wing tips as well. The outermost A-lines are connected to
the B-risers or the stabilo lines (see line plan, page 76). When inducing
a frontal collapse by pulling the A-risers, it is possible that only the
centre of the wing collapses while the wingtips remain open and move
towards each other. In an extreme case this could lead to a cravat. If
the above described event occurs (the wing tips moving towards each
other), this can be easily counteracted through a quick, symmetrical
pull of the brakes. As mentioned above, it is very important to immedi-
ately release the brake again.
This wing behaviour only affects frontal collapses induced by pulling
the A-risers. To avoid this behaviour during induced collapses, we re-
commend not just pulling the A-risers diagonally downwards, but pul-
ling them simultaneously inwards. This makes it possible to collapse
the wing tips as well.
Stalls
Spin
If the pilot brakes one side of the glider too much, a spin will result.
In a conventional turn, the axis of rotation is remote from the wing.
When a wing spins, the axis of rotation moves within the wing span.
The over-braked side of the wing slides back. The correct pilot reacti-
on is to immediately release both brakes. Occasionally it is necessary
to stop the canopy pitching forward.
Full stall
If both brakes are symmetrically pulled too far, a full stall will result.
This means that the wing loses its forward momentum, whilst the pilot
continues to travel forwards. From the pilot’s perspective it feels like
the wing falls backwards. At this moment it is essential that the brakes
are not fully released as there is a risk that the wing will dive - potenti-
ally underneath the pilot.
The available brake travel up to the stall point depends on the size of
the wing:
• approximately 56cm for the IBEX 3 XXS • 60cm for the IBEX 3 XS
• 66cm for the IBEX 3 S
These figures give a rough indication. Their inclusion in this manual is
required by EN 926. In turbulent air, a stall may occur markedly sooner
or later than these figures indicate. Therefore these figures only have
limited significance.
A full stall is a comp-
lex manoeuvre and
an explanation of its
correct execution is
beyond the scope of
this manual. Anyone
wishing to learn this
manoeuvre should
undertake an SIV/
pilotage course.
!
Содержание Ibex-3
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