KRONFELD ON GLIDING AND SOARING.pdf - Lakes Gliding Club

THE GLIDING AND SOARING SCHOOL 161
" But what about a plane that is not braced with wires
one that has a cantilever wing or only struts ? "
" Even then there are sounds. On every plane there is
something which vibrates to its motion. Even the tiny
eddies that form in the cockpit or round the flyer's head
sing their tune, though on good machines the music is not
so loud. But he who flies in them will already have
had so much experience that he no longer needs the great
orchestra of Aeolian harps which every wire-braced flying
machine is.
" This acoustic method never fails us. You may fly by it
through clouds, or through night and fog, where the eye
can distinguish nothing, or in the mountains, where the
view is limited. If you have practised it long enough, you
can always hear how your plane is flying.
" One drawback to this method is that each individual
machine has a different tone. You must familiarize yourself
with the music of each new plane you fly. There are
variations according to whether the machine is speedy or
slow, whether it has many wires or few or none. Often,
too, the sense of hearing grows dull during a long flight.
Then you distinguish only differences in tone but lose all
power to comprehend their exact meaning. Where there
are other noises which may easily overpower these, as for
instance, the roar of an engine, your acoustic sense may let
you down entirely.
"And now for the sense of touch ! In soaring, owing to
your open-air seat, you have an excellent opportunity to
feel the currents on your face. Darkness and fog make no
difference, but temperature and moisture do. We generally
think a cold wind much stronger than a warm one, and a
moist one differs from a dry one. But if rain or snow lashes
our faces, all power of discrimination vanishes/'
" Why don't we just fly by the sense of balance which we
have so strongly on the ground ? " a pupil now asks.
" Of that sense we can also make good use, but it is not
nearly so useful in the air as on the ground ; it may even
lead us astray, so that we form a deduction which is the
exact opposite of the true one.
" Often we feel the position of a plane quite clearly and
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