The L'Anse sentinel., 1923-08-10
Flying F'liivver
is Now Assured

move upward and downward as well,
is often overlooked because such cur
rents are rarely encountered near the
earth's surface, and never In areas
where the surface Is fiat and smooth.
Obviously, a down-moving current is
detected when 1t nears the earth, and
spreads out in sort of radial wind
movement. 1t Is plain, too, that an up
moving current cannot originate just
Mt the earth's fiat surface, because it
would cause vacuum there.
The currents by virtue Of which gil
ders can keep their altitude or even
climb, are not called winds, usually
defined as horizontal natural move
ments of air. They are sometimes
technically known as "wlnds with a
vertical component" Soaring birds.
such as hawks and eagles, the natural
gliders, take advantage of these up
ward-fiowing vertical or inclined move
ments Of air, to fly and climb for hours
at time without tapping their wings
or exerting themselves in any way ex-
cept to maintain their balance and
steer in areas where the air move
ment is favorable. There Is no doubt,
though, of course. there is no direct
proof, that these soaring birds have
an instructive sense Of rising or falling
"a sort Of exceedingly sensitive nat
ural altimeter-by which they pick out
the upward-moving areas Of air. Gil
ding is merely mans way Of initiating
the soaring birds. And man must use
his common sense and intelligence and
judgment in place Of the soaring birds
instructive sense Of rising or falling, to
spot the correct place to glide.
Some aeronauts prefer to call these
motorless aircraft "sailplanes" instead
of gliders, which Is the term more COM
monty applied. H. J. Nordman, inveD-
tor Of the craft that recently made
several flights over golf links near
Bayside, refers to his machine as
sailplane.
Downward Air Currents.
Glider pilots have to guard In par
ticular against the downward air cur
rents. 1t is obvious that In the total
of all air movements over the earth's
surface the speed and volume Of the
rising currents equal the speed and
volume of the falling currents. The
falling currents are what, in the pio-
neer days Of aviation, we're known as
"air pockets" regarded with dread.
The slow-fying airplanes Of those days,
like the Dewoitine flying fiivver, were
more subject to downward eddies of
wind and were less safe for that rea-
son. The faster plane is moving
through the air, the less effect will 1t
feel In reaction to air eddies, or
bumps" as the aviators call them.
This fact Is somewhat Of an obstacle
to the future popularity Of flying fiiv-
vers, which must be relatively slow
craft when not gliding. II It is to com
bine the elements of gliding and Of
powered flight.
The flying flivver's power equipment
is just sufficient to give the craft
start from level ground, without the
aid Of catapult or any other starting
device. And In the air the motor makes
II possible to continue flight In aerial
conditions that do not permit power
less gliding. The flying flivver driver
can fly In still air, or even in moderate
downward currents, and seek out areas
favorable to gliding. This the glider
of course cannot do. When the flying
fliveer pilot reaches an area In which
the air is rising, he can throttle down
or even perhaps "kill" his motor, and
fly his wasplike machine as glider.
A regular airplane can do the same
thing, to be sure; but not nearly SO
well. The larger motor of the ordi-
nary plane makes that much more
dead weight. And the relatively small
er wing area Of the aIrpIane built for
speedy flight Is incapable Of gliding
without '1osing altitude at a much
faster rate than the slower glider or
flying fiivver. and correspondIngly los
ing the advantage of the upward air
currents. In this instance, the slow
ness of the flying fiivver and the glider
Is the essential factor.
The gliding angle" Il the ratio of
the horizontal distance through which