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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.
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.
The manoeuvre has two phases:
• First the pilot weight-shifts into the turn and then uses the inner brake
to induce an ever tightening turn (note: do not jerk the brake, but pull
it smoothly and continuously). With increasing acceleration, there 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
These physical
demands can be
simulated in a g-force
trainer. We recom-
mend such g-force
training to all pilots.
!
Summary of Contents for DOUBLESKIN
Page 1: ...Manual _DE _EN ...
