KRONFELD ON GLIDING AND SOARING.pdf - Lakes Gliding Club

222 KRONFELD ON GLIDING & SOARING
The start must be made between the dropping of the
wind and the moment when the rain begins. The best
plan is to sit ready in the machine, with the starting crew
at the rope. The anemometer will indicate the moment
when the wind has attained the speed necessary for our
flight, and then we must not lose a second in starting our
flight before the storm.
At its commencement we must gain height as quickly
as possible, at the same time keeping the machine well
ahead of the storm. We are not yet very high, so that the
ground can still influence our flight, and if we possibly can,
we must avoid mountains which produce downwind. As
we rise, it becomes less and less necessary to trouble ourselves
about the contours of the earth below us, but all the more
must we study those of the thunderstorm. Quite suddenly
small, or even fairly large clouds appear in advance of the
front, and it requires sharp attention to avoid being
enveloped in one of these. The nearer the wall of cloud
draws to us, the more rapidly we rise, and the more difficult
grows the struggle with eddies and gusts. To tack before
the front as we do before a hillside, or to circle as we do
in normal cloud flying, is impossible before a thunderstorm
front, which is, however, generally so far-flung that
we can fly right along it in the direction we have chosen.
But when we are not quite clear as to which direction will
help us most on our chosen course, we must be very careful
not to fly too far at first.
If, by steady climbing, we succeed in reaching a sufficient
height to enable us to see over the storm, the second period
of the flight begins. This is known as the period of
orientation, and the higher we are for it, the better. Along
the whole front strong up winds prevail. On the boundary
between cold and warm air the storm discharges its artillery
of thunder and lightning, while its front stretches in the
form of a nebular roller which we can see beneath us along
its whole extent. There are now two things that we must
observe : the line of the front and the direction in which it
is travelling. It is easy to distinguish the line of the white
cloud roller below us, but hard to say in which direction,
from the standpoint of our starting place, it will expand