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If the speed bar is used as well, this increases sink and speed. This
also equalises the higher angle of attack caused by the increased drag
of the ears.
To release the ears, release the A-lines fully and allow them to return to
their normal flying position. If the ears do not open automatically, the
pilot can use a quick, sharp tug on the brakes to assist the opening.
2) B-line stall
A B-line stall is instigated by symmetrically pulling both B-risers (approxima-
tely 15 centimetres). It is recommended – for maximum grip as well as safely
executing the manoeuvre – to grab the risers at the top. i.e. at the maillon.
Immediately after pulling the risers, the wing will lose its forward speed and
after a short oscillation will descend in a stable parachutal stall.
When executing a B-line stall, we recommend watching your canopy – whilst
always keeping an eye on your height above ground, so that you are able to
exit the manoeuvre at the correct time.
The B-line stall is released by simultaneously raising your B-risers back to
their normal flying position. If they are released too slowly, an unintended
consequence can be a parachutal stall (see the section on parachutal stall).
The brakes should remain in your hands the entire duration of the manoeuvre
and no additional wrap should be taken. When exiting the B-line stall it is
important that the brake is completely free so that the wing can fully acce-
lerate to trim speed.
3) Spiral dive
The spiral dive is the most demanding descent technique and should
be learned at great height, preferably during an SIV/pilotage course.
The manoeuvre has two phases:
• First the pilot weight-shifts into the turn and then uses the inner bra-
ke to induce an ever tightening turn (note: do not jerk the brake, but
pull it smoothly and continuously). With increasing acceleration, the-
re will be a moment where the G-forces rapidly increase and the nose
of the glider begins to point to the ground until (during a successfully
performed spiral dive) the nose is nearly parallel with the ground.
• At this point the wing will reach sink rates of 20 meters per second
(m/s) or more. The acceleration can be more than three times gravita-
tional force (>3g). The pilot must be aware of these forces.
Before learning to spiral, pilots should practise controlled exits from
steep turns. These exits are performed by using the outer brake, whilst
the inner brake initially remains in the same position. The outer brake
is pulled until the rotational movement slows. To achieve a smooth exit
without pitching forward, the outer brake must be released more as
soon as the wing starts to level, i.e. as soon as the wing is no longer
horizontal.
The actual spiral dive – as outlined above – only occurs after the above
described transition phase, i.e. the diving of the wing. At this moment
the pilot is pushed outwards in his harness. The pilot should release
the pressure to avoid the wing locking into the spiral. Then the sink
rate can be varied using the inner and outer brake.
If the pilot’s weight remains on the outside, releasing the inner brake is
sufficient to continuously slow the rotational movement of the glider.
Exiting the spiral is then performed as described above.
If the pilot strongly weight-shifts to the centre, the glider may lock into
the spiral, regardless whether the brakes have been released. In this
case symmetrical braking or braking on the outside may help, as well
as weight-shifting to the outside.
In conclusion:
it is essential to practise this manoeuvre gently and in
stages. The exit must be controlled. Important safety information:
• if the pilot wishes to reduce the spiral or rotational movement, it is
recommended that the first action is to pull the outside brake, rather
than to release the inside brake;
• the pilot must be aware of the physical demands of rotation (vertigo)
and acceleration (g-forces).
• if the pilot weight-shifts to the inside of the rotation, the wing may
lock into the spiral;
• because of the fast descent rate, the pilot must constantly monitor
the height above ground and exit the spiral in good time.
These physical
demands can be
simulated in a
g-force trainer. We
recommend such
g-force training to
all pilots.
Summary of Contents for Ibex-3
Page 1: ...Manual _DE _EN ...
