Rapid Descent Techniques - Nova Mentor Light 4 Handbuch

_58

Rapid descent techniques

To quickly lose height, we recommend three possible manoeuvres. We
have ordered these by degree of difficulty:
1) Big ears
To apply big ears, the outermost A-lines must be symmetrically pulled
down. The brake handles (without an additional wrap) remain in your
hands. As long as the lines are held down the wingtips remain folded
and this increases the sink rate.
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
(approximately 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.
If the B-risers are pulled too far (markedly more than 15 centimetres),
the wing will slowly begin to rotate around its vertical axis. It is also
possible (particularly in turbulent air) that the wing horseshoes. This
means that the wing deforms and the wing tips go forwards. The ten-
dency to horseshoe can be reduced by gripping the B-risers from the
inside and then pulling them towards the body, as well as downwards.
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 accelerate 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, 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 gravitational
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.
_59 _EN