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26
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 Trango X-light² 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 rate increases 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
Big Ears 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 cm. 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 centralise over your
head. With 15 cm 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 until the wing is again stable
above you, showing the characteristic
deep crease along the B-level and
being fully stretched out span-wise.
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 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
