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RAPID DESCENTS
Spiral dive:
Big ears:
A spiral dive is the fastest way to lose altitude, however, the very high G-forces make
it difficult to sustain a spiral dive for long and it can place high loads on the pilot and
glider. By tensing ones abdominal muscles and a higher body tension you can to
some extent resist the high G-forces. Don't forget proper breathing! As soon as any,
even slight, light dizziness or impaired vision is noticed the spiral should be exited
immediately.
The Envy 2 has a very effective spiral dive. This allows rapid descent without stalling.
To enter a spiral dive the pilot should weight-shift on one side while slowly pulling the
brake gradually on the same side as weight-shifting. During a spiral dive the angle of
bank can be controlled by increasing or reducing the amount of inside brake. When
spiral diving the Envy 2 it is recommended that the outside brake is lightly applied.
This helps stabilize the wing and enables an easier and safer exit from the spiral. To
exit, release the inside brake slowly. The Envy 2 did not show a tendency to remain
in a stable spiral during testing. At high sink speeds or if the pilot keeps his weight on
the inside, the wing can stay in a continued deep spiral and has to be actively exited.
This is done by weight shifting to the outside and gentler braking of the outside wing.
WARNING!! Nearly all gliders will have a tendency to stay in the spiral if the sink-rate
exceeds around 15-m/s, depending on weight-shifting, wing loading and G-force. In
fact most gliders need a counter-input to end a turn.
Attention! Due to energy retention, the glider will climb a lot after a deep spiral-dive
release. If you apply inner brake and decelerate the glider for two or three turns, big
pendulum effects can be avoided.
WARNING!! Practise spiralling with caution and lower sink-rates to get a feel for the
gliders behaviour. A pilot who is dehydrated or not accustomed to spiralling can lose
consciousness in a steep spiral dive!
When in big-ears, the horizontal speed is higher than the sink rate, unlike a spiral dive or
a B-line stall. This rapid descent technique is used to quickly and horizontally exit a
dangerous area in the desired direction. In order to collapse the outside wing, pull the
outside A-lines.
When the pilot holds the outside A1-risers on both sides and pulls them down, the
Envy 2 easily tucks the outside wings and enters a stable descent mode. The pilot
keeps hold of the brake handles along with the outside A1-risers in his hands. By
braking on one side and weight-shifting, the canopy remains steerable.
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In order to increase the sink rate as well as the horizontal speed, this manoeuvre
should be done together with use of the speed system. Apply the speed system after
big ears are induced (step into the speed-bar before you grab the outer A1-risers).
Big-ears substantially reduces the risk of canopy stability problems in turbulent air. To
exit Big-ears release the A1-risers. The canopy does slowly self-recover. If not, or to
quicken the recovery, the pilot can gently apply brakes to the glider.
WARNING! Never do big-ears in spirals, as this may drastically reduce the number
of lines taking the already high loads, causing structural failure.
Attention! All rapid descent techniques should first be practised in calm air and with
sufficient height so the pilot can use them in emergency situations! By far the best
technique is to fly correctly and safely, so you never have to descend rapidly!
B-line stalls:
Summary:
To induce a B-line stall symmetrically pull down slowly on both B-risers, until the canopy
folds (parallel to its long axis). The airflow over the top surface is almost fully detached and
the canopy enters a vertical descent flight mode without forward movement. Further
pulling of the B-risers reduces the surface area more and increases the sink rate. (Up to 8
m/s) Be careful, pulling too far or too rapidly may cause a frontal horseshoe to form. To exit
from this flight mode release the B-risers at first rapidly but then gently (1 sec). The canopy
surges forward re-attaching the airflow over the top surface and resumes normal flight.
When the B-risers are released, the brakes should not be activated. This will give the
canopy the chance to gain speed and resume normal flight. On exit from a B-line stall on no
account just release the B-risers, as this can cause overloading. If canopy does not
recover apply both brakes gently to recover or pull the A-risers, until the canopy regains
forward speed.
For all extreme manoeuvres and rapid descents please note:
!
first practise manoeuvres with an instructor during safety training!
!
before inducing any manoeuvre the pilot must check that there are no other airspace
users below him!
!
during the manoeuvre the pilot must have the canopy within his view!
