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risk of a collapse is higher in accelerated flight. Additionally, the
reaction of the glider to a collapse in accelerated flight is more
dynamic compared to one which occurs at trim speed.
We recommend avoiding accelerated flight near the ground and to
be very alert when using the accelerator in turbulent conditions.
Use a soft speed bar, which enables you to accelerate the glider
by using only one leg., and use weight shift to control the direction.
To control the pitch, change the amount of speed bar. Do not use
or pull the brakes while using the speed bar. Use the speed bar
progressively when accelerating, and instantly release when you
feel a slight loss of tension, pressure or even a collapse. If you
encounter a collapse while using the accelerator, release the speed
bar immediately before taking any other corrective action. Always
keep more distance from the ground when using the speed bar.
Active flying
This is a basic flying technique for any pilot. It implies permanent
control and the correction of pitch and roll movements together
with the prevention of any deflations or collapses. In a nutshell
this means flying straight through active or turbulent air, so that
the pilot keeps the glider vertically above their head at all times,
compensating and correcting any unwanted movements of the
wing.
Few examples:
• While entering a strong thermal, the wing will stay a little bit
behind relative to the pilot. The pilot should ease the brakes
up, allowing the wing to fly faster and to catch up.
• If the wing surges in front of the pilot, the pilot should counter
brake until the surge is controlled and then release the brakes
to let the glider fly normally.
• If the pilot feels a loss of tension on the wing or a loss of
pressure on the brakes on one side of the wing, he should
smoothly apply the brake on the side with loss of pressure and/
or weight shift to the opposite side until the pressure returns.
After that, again release the brake and/or weight shift to the
neutral position and let the glider fly normally.
The key in all cases is to avoid an over-correction and not to
maintain any correction longer than necessary. After each action
let the glider fly normally again, to re-establish its required flying
speed. You can train or get a feeling for most of these movements
safely on the ground while ground handling your glider. Good
coordination of your movements and coordination with the wing
on the ground will enable you a quick progression when actively
flying in the air. The next step is to attend SIV clinics, where you
should also get a better understanding of the full brake range and
the glider’s speeds.
Flying in turbulence
Wing deflations (collapses) can occur in strong turbulence. The
D-light is designed and tested to recover without pilot input in
almost all situations, by simply releasing the brakes and letting the
glider fly. To train and understand all the manoeuvres described,
attend SIV clinics.
Cascade of events
Many reserve deployments are the result of a cascade of
over-corrections by the pilot. Over-corrections are usually not
problematic because of the input itself or its intensity; but more
due to the timing of the pilot input. After every input you have to
allow the wing to re-establish its normal flying speed. Note that
over-corrections are often worse than no input at all
, particularly
on EN A wings like the D-light.
Asymmetric deflations
Strong turbulence may cause the wing to collapse asymmetrically.
Before this occurs the brake lines and the feeling of the harness
will transmit a loss of pressure to the pilot. This feedback is used
in active piloting to prevent a collapse. If the collapse does occur,
the D-light will easily re-inflate without pilot reaction, but the
wing will turn towards the collapsed side. To prevent this from
happening, turn and actively recover the asymmetric collapse by
weight shifting and applying appropriate brake input on the side
that is still flying. Be careful not to over-brake your wing’s flying
side. This is enough to maintain your course and give the glider
enough time to recover the collapsed side by itself. To actively
reopen the collapsed side after course stabilization, pull the brake
line on the collapsed side firmly and release it. You can do this
several times with a smooth pumping motion. After the recovery,
release the brake lines for your glider to regain its trim speed. Note
that asymmetric collapses are much more dynamic when flying
accelerated. This is due to the difference in weight and resulting
inertia of the (light) canopy and the (heavy) pilot hanging below.
Symmetric deflations
Symmetric or frontal deflations normally reopen immediately
by themselves without pilot input. The glider will then regain its
airspeed accompanied by a small surge forwards. To actively
control this event, apply both brakes slightly when the collapse
occurs and then instantly release the brakes to let the glider fly.
Be prepared to compensate for a slight surge forward while the
glider regains normal flying speed.
Wing tangle, cravat
The D-light is very unlikely to cravat, but it may occur after a
severe deflation or in a cascading situation, when the wing tip gets
caught in the lines. Pilots should be familiar with the procedure for
handling this situation with any glider. Familiarize yourself with the
stabilizer main line (“stabilo” line, orange colour) while unpacking
and preparing the wing. If a cravat occurs, the first thing to do is
to try to keep the glider flying in a straight line. Do this by weight
shifting and counter braking the untangled side. After that, grab
the stabilizer main line on the tangled side, pull it down until it
becomes tight again. At this point the cravat normally releases
itself.
Possible solutions of the cravat situations (consult your SIV
instructor):
• Pulling the wing tip “stabilo” line
• Using a full stall, but it is essential to be very familiar with this
manoeuvre. You also want to have a lot of altitude.
• If you are in a situation where you have a cravat and you are low
in rotation or even with twisted risers, then the only solution is to
deploy the reserve parachute.
Negative spin
In normal flight you are far from negative spin. But, certain
circumstances may lead to it. Should this occur, just release the
overbraked line progressively and let the wing regain flying speed.
Be prepared for a canopy surge forward, and compensate the
surge with brake input if necessary.
