The Coolidge examiner. [volume] (Coolidge, Ariz.) 1930-current, 1933-11-17

vealed in an odd experience related
by Major Won Tschudi, a German
aeronaut. Cruising one day in a
balloon, he saw, far below him and
off to one side a flock of storks
soaring along. Suddenly TO his
amaZement they rose almost verti.
cally without so much as a flap of a
wing. Soon they passed the ele-
walton at which his balloon was fly
ing and went on up far above him
While he was still wondering at this
marvel his balloon which had been
travelling horizontally reached a
point about over that from which
the storks had started upward. Then
the balloon too began to rise rap
idly as If by magic force. 81 know
now after what gliding has taught
u.s." said this airman, that had
simply struck one Of those vertical
air currents, the same current on
which the lazy storks were taking
a free ride up to higher altitude. "
In Germany today some 200 glider
clubs exist and probably about
10000 flights and short glldes are
made annually.
Between gliding and what they
call sail flying" the Germans make
a sharp distinction. During a glide
the plane steadily loses altitude till
II lands. A sail flight" on the con
trary is one in which the machine.
while pointing downward, is lifted
by upward air currents, and thus
either maintains or increases its ele-
walton.
For training a beginner in motor
less flying the simple glider is used /;
but 1t is the sail plane which actn-
ally flies. In build it is more sensi
tive than a simple glider and
capable of responding to vertical air
currents.
Weighing from 200 to 300 pounds,
but with a wing surface of more
than 20 square yards, light sail
plane easily floats upward on an air
current, carrying its rider with it..
But the pilot does more than ride.
Fitting snugly into the body of the
structure itself, the flyer feels al
most as If he himself were equipped
with wings and tail This similar
ity is apparent. as one watches a
skillful flyer manipulating his sail
plane. Pilot and plane seem one en-
tlty; every movement of the plane
is a movement of the man inside,
and vice versa.
Features Of the Sail Plane.
Flying plane with no motor in il
seems less miraculous to the man
on the ground when he hears how II
is built. The conspicuous feature
of the sail plane is its very long.
narrow wings-sometimes as much
as SO feet in length and less than =
feet In width. Narrow the wings
must be. for broad ones could ere
ate too many eddies. and long they
must be TO provide the surface to
lift a mans weight.
While simple gliders often start
merely by sliding or being dragged
down hillside, so light In struc
ture Is the sail plane that were il
started slowly 1t would only tumble
about like thistledown In the wind
and get at once out of control
Hence. In launching, an elastic rope
is used, which shoots the plane into
the air like stone from a sling.
The pilot must maintain this
speed by pressing down the nose of
the plane. which decreases the angle
of the tilt of the wings. The earth's
gravity will then draw the plane
downward in a gentle slanting line
of flight, which Is called a glide
Thus the gravity of the earth is
the engine Of the engineless air
plane.
The fact that the sail plane con
tinues to glide downward while the
vertical air currents are carrying it
up may seem TO some as Involved
as Einstein's theory of RELATIVELY ;
but when one studies the explana
ton which Robert Kronfeld. one of
the instructors at fbp hvinp SchooI
in the Rhon mountains, gives to his
pupils, this phenomenon ceases to
appear mysterious. Suppose you
let a glider fly down from the cell
ing at one end of a room to the
iloor at the other end" he tells
them. land imagine giant lifting
the whole room high up into the air
then the model plane would be gain
ing an altitude while gliding down
ward"