Evening star., 1940-07-21
A|.ifp1ane Factories
Have No Substitute
For Handwork
From Design to Finished
Product Requires Up
To 20 Months
BY DEVON FRANCIS,

SANTA MONICA. Calf, July 20.
After 81 years. the airplane is still
= handmade product.
One statistician has Inquired that
It will require the work of close to
100000 persons to turn out the 50,-
900 planes a year President Roose-
welt has asked. That many persons
ir the automotive industry can turn
out trucks and passenger cars by the
millions.
Fifty thousand airplanes will
mean the addition of at least 400,-
900 men to the shop personnel Of
the aircraft factories. It will mean
the addition of other tens of thou.
sands to the payrolls of related in
dustries which supply machine tools
and materials.
Airplanes remain handmade
product, expensive and slow in
manufacture, largely because of the
metal which goes into them.
That metal is an aluminium alloy.
Pound for pound, it is the best con-
struction metal for planes which
engineers have found since the
Wright Brothers first flew in 1908.
aluminium Wings Stronger.
Against stainless steel aluminium
is not only much less expensive but
1t is also stronger. Stainless steel
wings, with which this industry has
experimental, must be reinforced in
side with corrugated backing" to
make them take the abuse to which
aluminium is subjected.
A piece of aluminium interior wing
structure in almost constant flight
for six years was removed the other
day from an airliner and purposely
was bent until it broke. It showed
practically the same strength as the
day it had been installed In the
plane.
Here at Douglas Aircraft Co.
plant, one of the largest in the
United States. $4,000 persons are
fabricating both warplanes and
commercial transports with that
slow, meticulous workmanship which
Is typical Of the industry.
Night and day three shifts of men
fashion winged monsters. Under II
acres of roof riveting hammers
sound in concert.
Almost every rivet-some types of
planes contain as many as 800 1000
must be inserted individually and
tapped down with air-driven ham
mers. Two men are assigned to
each hammer. Some spot-welding is
being done. but none of it, as yet,
Is tried on parts built to Withstand
such stresses as are set up in the
@pull-outs" Of dive bombing.
20 Months for Manufacture.
Actual construction is only part OF
the tedious process of plane manu-
facture. Usually 20 months are re-
quired for the conception of an idea
for a new plane and the actual
production Of the test plane. Then
additional weeks are required for
testing.
Airplanes develop strange quirks,
sudden ailments and the whole de-
sign must be returned to the engi-
neers for study
At one. Southern California plant |
1t was discovered after 70 planes OF |
q given type had rolled of the as
sembly line that all of them were |
heavy" on the right wing. They
unanswered badly. The engineers,
investigating, discovered a guide
rivet hole in o. Gig" steel frame
work in which airplanes are built,
was quarter inch out of line. The
mistake required the reconstruction
Of 40 wing panels.
Another quirk which afiicts air.
planes is a shift in the center OF
gravity. At the Douglas plants big
final assembly hangar three scales,
graded to the f1neness Of an apothe-
cary's, are sunk into the concrete
flooring.
Every plane leaving the factory
is weighed. landing gear to tail
wheel, to determine its net tonnage
and weight distribution.
Weight Distribution Vital.
Weight distribution is so impor-
tant that small-plane owners con-
stantly are warned by insurance
companies to clean the accumulated
dust from the rear of their fuselages.
A few extra pounds there will cause
a fatal spin.
Both business and an art, air
plane manufacture has developed its
own specialists. In the Los Angeles |
area, where the $4,000 shop en-
ployes probably will be doubled be-
fore the close of the year, men who
work on the big shells which become
transport cabins or the interiors OF
bombers are known as trainers,
skinners and riveters.
The trainers put the skeletons to-
gether. The sskinners apply the
broad metal lath which covers the
skeleton and attach it temporarily
with spring inserts in the rivet
roles and the riveters complete the
Job.
A new technique in riveting has
been developed in the last couple OF
years. Flush rivets," shaped like
flat-headed screws, are tapped into
place on the leading edges and part
of the top of the wing to accelerate
the flow of smooth air. That in
creases the lift and the speed.
A housewife couldn't be any more
careful with a cake ready for the
oven. ....