Dudek VOX-25S, User Manual

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7. Rapid Descents
SPIRAL DIVE
Spiral dives as explained previously have a rapid descent rate, 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. Never do these in turbulence or at
too high bank angles.
If done in strong winds the pilot may drift off course.
NEVER DO BIG EARS IN A SPIRAL!
Tests have proven that loads can be developed higher than those used in
certification tests, which could result in structural failure of the glider, as less
lines are taking these high loads.
BIG EARS
The outer cells of the wing tips may be deflated by pulling down the A"
raisers (blue band) simultaneously by approximately 50 cm.
It is important to not let go off the brake toggles while entering the Big Ears
manoeuvre.
The canopy remains completely controllable through weight shift. It
maintains straight flight but with an increased sink rate (up to approx. 5
m/sec).
On releasing the A"-raisers the canopy usually reinflates by itself, or can be
aided by a long pump until tips clear.
B - LINE - STALL
To induce a B line stall pull both B - risers simultaneously by 20 - 30 cm. The
airflow over the top surface is detached and the canopy enters a parachutal-
stall without moving forward.
Further pulling of the B-risers reduces the surface area and increases the
sink rate (to approx. 10 m/sec) and leads to bigger wing unstability.
On quickly (symmetrically) releasing the B lines the airflow over the top
surface becomes reattached and the canopy surges forward to return to
normal flight.
If canopy does not recover see section "Deep Stall".
In the possibility that the canopy forms a frontal horseshoe, apply both
brakes gently to recover.
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