Evening star. [volume] (Washington, D.C.) 1854-1972, 1931-08-30
AVIATION
BY WILLIAM w. CHANCE.

of the frontal area, though this move
ment was checked by the development
Of affective cowling rings for the radial
engines which increased speed by
smoothing out the flow of air. The APP
proved engine types range from a little
3-cylinder motor producing 80 horse
power to 12-cylinder giant turning UP
800 horsepower.
Those who have delved into the De-
partment of Commerce records with a
bright eye and statistical mind have
found that wood and fabric have been
giving way to metal for airplane con-
struction at a fairly steady pace In
addition to duralumin, stainless steel
and alloys of magnesium have come
into general use, with other and better
alloys appearing on the horizon. One
Of the new types Of construction APP
pearing in recent designs is the metal
monocoque fuselage-a type which is
both civil and military fields. The
type is built like a shell. the
covering being called upon
to contribute part Of its strength.
Light Planes Popular.
Very noticeable during the past six
months has been the trend toward
light airplanes, defined by the Depart
ment of Commerce for licensing pur-
poses as heavier than-air aircraft of
less than 1000 pounds gross weight.
with a maximum wing loading of SIS
pounds per square foot and having at
least square feet of wing area per
engine horsepower"
The light planes with large wing
area take-off with a short run, have
low landing speed and are easy to fly
and to operate from small fields. They
are economical to operate because of
their small size and low horsepower,
and are largely intended for pleasure
flying.
Though the metal propeller has come
into almost universal use, there still
is demand for wooden propellers for
engines of less than 100 horsepower.
used on planes which generally oper-
ate only 1rregularly and which there
fore do not present problems Of upkeep
as acute as those of the transport
planes. which fly a grinding daily
schedule.
Considerable research has been d.
rected toward the development of con-
trollahle pitch propellers. the depart
ment's approved type propeller certifi-
Gates show. These propellers are de-
signed to provide varying angles of at
tack, and so to operate most efficiently
at all times during the take-offs,
climbing and cruising.
AirpIanes and Dry Ice.
Believe it or not, says one Of the
country's foremost airplane builders,
dry ice is used in building airplanes.
The dry ice is used in the treatment
of duraIumin rivets, which have a
tendency TO become too hard for ef-
fective use after they have been heat
treated.
To arrest this hardening the rivets
are stored in boxes in which dry ice
is placed Immediately after they are
heat treated. The sudden chilling, 1t is
said, prevents the rivets from harden
ing. approximately 100 pounds Of dry
ice are used weekly in the plant Of
this builder alone.
The same manufacturer has as
sembled what is believed to be the
most complete and accurate group of
scale models of airplanes ever collected,
now on exhibition in Seattle. Produced
by the companys model-building de-
partment, the collection comprises 81
airplanes. replicas Of various
types Of aircraft produced by this COM
pany The collection Is valued at
SIC, 900.
New Air Transport Records.
The first six months Of this year
witnessed the establishment Of new
records for mileage flown and mail
and express shipments carried by the
Nations air transport planes, accord
g. -.
to the Aeronautical Chamber of Com
nyrce.
During the half year American
transport planes. flying ON regular daily
schedules, travelled total of 1922, ATS
miles, as compared with 1924, 32i
miles during the same period last year
The percentage OF increase was 49.2,
a most healthy rate Of increase.
During the six-month period the air
lines Cancelled or failed TO complete
only 81 per cent Of their scheduled
flights despite the fact that a great
deal of unfavorable weather was en-
countered in certain sections Of the
country, especially in the vicinity Of
the National Capital and New York.
Airmal flown during the six months
averaged 1880 pounds more per
month than during the first six months
of last year. the poundage for the haR
year tota1ing 4.523432, or a Is per
cent increase over the total hown by
the aerial poStn1en during the same six
months of last year.
Express shipments IN the first half
Of this year reached a total Of 36T, TAO
pounds nearly three times as large as
the amount handled during the same
interval last year, when l3s,064 pounds
were carried.
Passenger Traf5e Grows.
Passenger trafic handled by the
ma jor lines showed a gain of approx
mately 10000 during the first six
months over the first six months of
last year, though the total number car
ried on all lines was slightly less than
a year ago during the boom" period of
passenger travel The number Of pay
passengers flown during the first half
Of 1891 was 1918 as against 1872, 979
during the same period last year. The
decrease Is held to have been due 70
the falling of Of thrill riders during
the opening days Of operation Of many
OF the shorter lines. this being followed
by q building up Of steady passenger
trafic, which is continuously increasing.
The modern transport plane is a
thoroughly complicated piece Of fab
rication. A survey recently made shows
that total Of 1912 separate parts
are used in the assembly OF Boeing
trimotored transport plane. OF this
total 6o.3S3 parts we're produced from
special drawings The balance OF $3.50
parts included bolts. nuts, rivets and
similar standardized parts.
HORSES REPLACE TRUCKS