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Section 7
Dangerous situations and extreme flying
Other tips for dangerous
situations
Stalling in rain
In general, there are two reasons why a
paraglider may go into deep stall in rain:
1. The first risk lies in the fact that the canopy
weight increases if a glider is flown in rain for
any length of time. The centre of gravity and
angle of attack then shift, which can result in
airflow separation/stall. It is relevant here that
if a glider absorbs more water (as older
gliders do because they lose their water-
repellent coating over time) and is closer to
the deep stall limit because of its design and
age, less water absorption and thus weight
increase will put the glider into deep stall.
2. When there is rain, there can be so many
water droplets on the top surface of a glider
that almost the entire upper surface is
affected but, even so, the drops “bead” so
the surface is not wet through. This makes
the top surface so “rough” in texture from the
drop formation that the airflow over the top of
the wing separates from the surface. This
phenomenon has been known for some time
from hang-gliding and gliding. With new
gliders, the droplets are absorbed less
quickly by the fabric. Thus, the newer a glider
is, the greater the number of droplets caught
on the top surface and the bigger those
droplets are, the greater the risk that there
could be airflow separation. We were able to
recreate these conditions by practical tests
and computer simulations, but they occur
very rarely.
It is the case in both of the above situations
that the control travel and braking distance
first reduce and then the deep stall is
caused, mostly by alteration of the brake
travel or angle of attack, e.g. by a gust or
thermal.
WARNING
Flying in extremely humid weather or in
rain is outside the operating limits of the
glider. If you are not able to avoid flying in
rain, please observe the following:
It is advisable to fly with slight
acceleration during and after the rain
(min. 30% or more)
Use no brake input or as little as
possible
Do not use big ears
Control travel reduces
Avoid tight turns, especially in the final
approach. If conditions allow, you
should also fly slightly accelerated in
this phase
Avoid large angles of attack and the
possible early stall near the ground
(release the speed bar only slowly)
Advertising and adhesives
Always make sure before attaching
advertising to the glider that the adhesive
planned will not alter the glider’s flight
behaviour. If you are in doubt, we
recommend that you do not attach the
adhesive.
PLEASE NOTE
Attaching adhesives to the glider which
are large, heavy, or made of unsuitable
material may result in revocation of the
certification.
