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28
Steep Spiral Dive
A maximum sink rate of over 15 meters
per second can be achieved in a steep
spiral dive, but it is advisable to build up
gradually to these sink rates when you first
practice spiralling.
Getting the UP Summit XC² into a spiral
dive is very simple and has already been
described in the chapter regarding turning.
When entering the spiral it is essential to
induce the turn gradually; if you apply the
brake too quickly you may enter a spin. If
this happens, release the brake
immediately and let the glider recover
before trying again. Keep a steady tension
on the inside brake and observe the
increased angle of bank and sink rate. A
little brake on the outer wing will help
stabilize the glider at a high sink rate.
As the sink rates increase the inner
(lower) wing tip will begin to deform; this is
a design feature that improves the passive
safety during the manoeuvre.
To recover from a spiral, simply release
the inside brake. Do this gradually to
prevent an uncontrolled steep climb
caused by the excess energy built up
during the dive. Be prepared for the glider
to climb a little and to damp out the
subsequent dive. Be warned that steep
spiral dives are equal to high G loading on
both you and your glider!
WARNING! Spiral dives with
high sink rates expose the
pilot and material to very
high centrifugal forces
–
incidents caused by pilots
falling unconscious during spiral
dives are not unheard of. Approach this
manoeuvre with caution. NEVER fly a
spiral dive with BigEars engaged
– this
could lead to a catastrophic material
failure!
B-Line Stalls
To induce a B-line stall, start from
normal, un-accelerated flight. Reach
up and take hold of both B risers, still
with your hands in the brake loops,
and pull down simultaneously by
approximately 15 centimetre. The first
few centimetres of travel will be quite
hard, but as the glider settles into the
stall so the effort becomes less.
The glider will drop back a little as it
stalls, and then centralize over your
head. With 15 centimetre or so of pull
a sink rate of up to 9 meters per
second can be achieved. With less pull
you will get a decrease in sink rate.
The B-risers should not be pulled
beyond this point, as it may result in
the canopy entering an unstable phase
or going into a frontal rosette. Should
you inadvertently have pulled too far
down on the B-risers, simply release
them a little again until the wing is
again stable above you, showing the
characteristic deep crease along the
B-level and being fully stretched out
spanwise.
To recover from a B-line stall, the
risers should be released abruptly and
simultaneously. Doing so will allow the
wing to re-inflate completely and
resume normal flight. It is not unusual
for the canopy to dive in front of the
pilot as the wing regains speed, angles
of up to 30-45° are not perfectly
normal. In this phase the pilot should
NOT engage the brakes!
WARNING! Releasing the
B-stall too slowly, or
asymmetrically, can
lead to dangerous
situations. Always practise
manoeuvres under
professional guidance and over water!
