30
n.
Going down fast
Most pilots will, at some time, want to lose height. This may be because of a change in the
weather, you are at cloudbase and don’t want to go any higher, or simply because you want to
finish your flight quickly.
Ideally, the best way to lose height is to find an area of sink and stay in it. This way you can fly
normally to the ground. However, if there is no sink, or if you are in strong lift and want to go
down, a rapid descent method may be needed.
There are three main rapid descent methods:
•
Spiral Dive
•
B-line stall
•
Big ears
Each of these descent methods places extra, different stresses on gliders and should be
avoided if you want to extend the life of the glider.
It is important these manoeuvres are initially practiced under qualified supervision and
preferably during a safety training course.
i.
Spiral Dive
The spiral dive is an effective way of making a fast descent. During the spiral dive the pilot and
glider will experience strong centrifugal forces which strain the glider. As such it should be
considered an extreme manoeuvre. Due to the rapid height loss during a spiral, pilots must
always take care that they have sufficient altitude before initiating the manoeuvre.
Initiation: Weight shift and smoothly pull on one brake (the same side you are weight shifting
into) so the glider goes from a normal 360-degree turn into a steep turn and from there into a
spiral dive. Once established in the spiral the descent rate and bank angle can be controlled
with weight shift and the releasing or pulling of inner brake. As the glider banks in front of the
pilot maintain the spiral by keeping the brake pressure constant, at this point weightshift can
be neutralised. Descent is controlled by pulling more on the inner brake. A slight pull on the
outside brake helps to keep the glider stable.
Recovery: The RISE recovers from a spiral spontaneously as soon as the brakes are released
and weight shift returns to neutral. To exit, allow the spiral to slow for a turn or two by slowly
releasing the inner brake. Once the glider starts to exit the spiral, control your descent rate and
bank angle with weight shift and the outer and/or inner brake to prevent any strong climbs out
of spiral. Always finish a spiral dive at a safe altitude.
The RISE does not show any tendency for a stable spiral ie. the glider does not remain in spiral
after releasing the brakes. If the glider should, in rare cases, remain in a stable spiral the pilot
first should weight-shift to the outside and brake slightly more on the outside.
