22
Section 05
Flying the TWIN RS 2
upcurrent
from
a
cumulus
cloud,
an
approaching cold front or a storm front.
Rapid descent methods should all be practised
in calm conditions and at sufficient altitude so
that a pilot is then able to employ them
effectively if extreme conditions arise. The rapid
descents are divided into three different
manoeuvres which increase the sink rate in a
safe and controllable manner.
Spiral dives
WARNING
In the spiral dive, very high turn speeds can
be reached with an increase in acceleration
due to gravity (up to over 6g), so exercise
care when attempting this manoeuvre. Take
note of the following:
Do not enter the spiral dive by way of a
wingover. High sink rates can be reached
very quickly by doing this. It is not possible to
safely gauge the sink rates.
Do not continue the spiral dive for too long: it
could cause a loss of consciousness.
Always maintain ground clearance of 150 –
200m
.
The manoeuvre must be exited at
this height above ground.
Spiral dives with “big ears” lead to extreme
loading of the open section of the canopy.
This move is prohibited in Germany.
The spiral dive is the most effective method for
making a rapid descent, and can allow sink
rates of up to 20 m/s to be reached. It is
suitable where there is a high ascent rate and
little wind.
The certification tests differentiate between sink
rates over and under 14 m/s. The TWIN RS 2
automatically recovers from the spiral dive
within one turn up to 14 m/s. Above 14 m/s, it
may be necessary to break the outside half of
the wing and/or weight-shift to the outside to
recover from the spiral. With a sink rate up to
20 m/s and a neutral position of the pilot, the
spiral does not tighten automatically.
Exiting the manoeuvre at high sink rates can
take several turns.
Given the complexity and the possible risks of
the spiral dive, SWING recommends that this
manoeuvre be learnt under qualified instruction.
The G-forces with the TWIN RS 2 can be much
higher than 5G, depending on the angle of bank,
if the spiral is not controlled using the outside
brake.
Starting the manoeuvre
Begin the spiral dive whilst flying at full speed by
flying a turn which becomes tighter and tighter
and by using weight-shifting to the inside (refer
here to “Turns” also).
The bank angle and sink rate are controlled by
carefully applying or releasing the inside brake
and by gently applying the outside.
Look down before and during the spiral dive to
maintain a constant check on your distance
from the ground.
TIP
The outer wing tip may collapse during the
spiral dive although this is no cause for
concern. It can be avoided by lightly braking
on the outside. Release the brakes carefully.
Recovery
Recover from the spiral dive slowly and steadily
over several turns. The inside brakes are
gradually released. If the brakes are released
too quickly, the increased speed can cause the
wing to climb, become unsettled or partly
collapse. Recovery can be assisted by braking
lightly on the outside.
DANGER
At a high sink rate (above 14 m/s) it may be
necessary to brake the outside half of the
wing and/or to use weight-shifting to
recover from the spiral.
Furthermore, for exiting the manoeuvre,
several turns with a corresponding loss of
altitude may be required.
You must immediately deploy your reserve if
you lose control of the glider and the sink
rate and find yourself in a stable spiral.
The spiral may lead to loads and/or
disturbance to consciousness which prevent
later deployment of your reserve.
