Evening star., 1928-05-20
PLANE BUILDERS GET AID
AT LANGLEY LABORATORY
National Advisory Committee for Aero
nautics at Work ON Many Problems
to Make Flying Safe.

brought to bear on pia~c Iii sucn
maneuver It told what TO expect from
the flow of air over airplane wings.
And. incidentally, 1t confirmed the sta
biIity of American-built pursuit planec.
the Boeing's colleague. the Curtls5
Hawk, having previously stood the
knocks.
Water Weight Found Half.
And as to a comparatively simple
little test relating to the water pressure
distribution on a pair of seaplane pom
toons The figure was found to be
pounds per square inch. What OF 1t?
The design called for Is pounds as a
safety factor The difference between
the two could be saved in weight
weight which is the bane Of the design
erS existence. With weight saved there,
a little more here and so on, increased
speed. less fuel consumption, bette per-
formance and other advances result.
All toward the perfect airplane.
Every wing is not alike. There are
many different types, some that have
great lifting power and hold back the
speed Of the plane: others that nave
IittIs mting power. but contribute more
to speed. There are still others in be-
tween. These wings bear certain deSig-
nations and numbers.
BY means o. the equipment In he
form of wind tunnels at the laboratory
the research engineers are able 70 learn
every characteristic OF these various
wings, which are constantly being built
toward the perfect airplane. They know
by measuring the flow of air over them
what the lifting qualities are; they
know by subjecting them to intense
pressure what their ability to stand up
under great strains are; they know the
amount of drag" or resistance they
create-all of this being under the head
Of aerodynamicS.
Today a designer has but to cali on
the committee for the characteristics OF
various wings. pick out the one neSt
suited to his purpose. and with the
blue print set about constructing the
aerofoil. Assuming the construction IS
good and solid, the wing viii serve his
purpose. The committee concerns itself
with the aerodynamic features OF the
problem.
In its studies of wings the committee
has dwelt on authorization" or hat-
spinning. a laneuysr in which an aero
dynamically imperfect airplane whirS
around lateralIy as it falls TO earth It
is difficult to recover from these nat
spins, as the controls usually IAN 70
respond. owing to the presence OF
vacuum around them.
Wing That VIII Not Spin.
The committee has found that
monoplane viii not hat-Spin, and that
a biplane may be rendered immune oy
"a proper amount OF stagger, Wnlcn
calls for attaching the lower wing far-
ther from the top one, so that they are
not directly beneath one another. Is
now Is working on a wing section that
will not spin.
Included in the equipment for the
aerodvnarnic studies are three wno
tunnels-the atmospheric. the varlanle
density. and the propeller research tun-
nels The first is large horn-shaped
effect in which wing models are in
serted and a big fan turned on at one
END which forces air against the mooeI-
The wind speed in this tunnel reaches
close 10 go miles an hour. a terrinc
speed from the standpoint Il the scaie
model Little holes are In the Wing
model and these are connected VII
recording instruments wnicn catch
every popularity OF the now OF an
cantic steel subnarine-line apparatus.
/ in which pressures I'D to 800 bounds per
scuare inch can be maintained LIE
I effect of these preSSureS on moceis =
I closely studied.
Propeller Test Tunnel
The propeller research tunnel. re-
GENTLY placed in operation. accommo-
dates a ftlli-sized airplane and gives
the experts information equal TO tna.
obtained from an airplanc N nignt. u
such could be recorded. This tunnel
Is composed Of two huge cones. sep
arated by space. in which the airplane
is mounted.
An enormous fan. bearing eight
blades. each of which Is Is feet IA ci.
ameter and operated by two Diesel
submarine engines, each OF 900 horse
power. is turned on, 1t sucks the an
| from one cone TO another and the plane.
/ in between the two and in the terrtnc
rush of wind. Is observed under actual
/ flying conditions,
At the recent conference this ian
/ generated a wind velocity Of % miles
per hour A pilot was in the mounted
/ plane and he held the engine at fuu
/ throttle. Under these conditions every
/ characteristic Of the propeller. which
/ had been perplexing problem because
OF the inability to obtain firSt-hand m
/ formation as 20 its performance. 5
/ studied in addition to the reactions Of
/ ths ulane proper under these flying
conditions