Evening star., 1940-05-30
Tools Needed to Build Planes
Delay Production for Year
Martin Opens Plant to Aviation Writers;
Reveals Latest Mass Methods

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one OF the small private-own air
planes now being produced in larger
quantity than any other type Of air.
craft, and the tremendous total of
$4,000 man-hours of work are re-
quired on a large bombardment air.
plane.
The visiting aviation writer's were
taken through large, completely
equipped chemical laboratories at
the Martin plant in which expert
mental work is in progress on self
sealing fuel tanks, metals and alloys,
plastics and plywoods for possible
use in aircraft production. It has
bene found that under production
methods now available the use Of
the improved plywoods, which are
exceedingly strong and resistant to
moisture and fire. is about, equal in
cost to use of metals.
Extensive experiments have been
conducted in development of armor-
plating for protection of pilots and
crew members, no figures having
been available in the past for thick
nesses OF metals suitable for the
purpose. Since weight-saving is a
vital factor in airplane construction,
the question of armor presents an
exceedingly serious problem; it can
be used only at the cost of airplane
performance, most noticeably in
take-off and rate of climb.
Due to precision methods of manu-
facture introduced by extensive use
OF machine tools and straight-line
practices, all parts of the Martin
aircraft of the same models are in
terchangeable. This proved a great
surprise to the French, who were ac-
customed to having wings tailored"
to particular fuselage and to parts
which would fit only the airplane
for which they were built.
Finished Somewhere in Europe.~
AS a result Of these precision
methods, 1t was necessary to fly
only the first of the French airplanes
in this country before it was shipped.
The others now rolling off the pro-
duction line, at rate said unofficiallv
to be about three day, are shipped
abroad before final assembly and
never become complete airplanes
until they leave the hands of an
American assembly crew "some-
where in Europe To maintain a
check on production accuracy, how
ever, one airplane out of about Is
actually is assembled at the Martin
plant and then is broken down and
ooxed Tor shipment-each airplane
in crates costing $1,000.
Scores of the twin-engined French
bombers are in process through the
assembly lines in the Martin plant.
a trip through the plant revealing
graphically every stage of the man
utacturing process from the stamp
ing OF the smallest metal fitting to
the boxing of the completed fighter,
with its red-white- and blue insignia
and instructions, in French. stem
clled on the metal in various parts
of the ship.
Another section of the plant now
is being fooled for production of
the new model Martin bomber for
the United States Army Air Corps.
soon to go int production. Heavy
steel jigs, or assembly frames, are
being set up in such numbers as to
beWilder and confuse the observer.
In these frames will be assembled
the various component parts of the
airplanes, which then will move to-
gether along the assembly line.
flowing together" into the COM
pleted airplanes.
Prepare for New Plane.
Work also is in progress on the
preparation of the necessary tools,
dies and jigs for a new series of
Anglo-French combat airplanes
recently ordered by the Allied Pur-
chasing Mission. 1t will take nine
months more to complete this tool
ing up and start production of the
new Allied planes and the complete
order, for an unannounced number
of planes, is to be completed in nine
months more.
Among the new tools now being
put into the work of producing air.
craft at the Martin plant is an auto
matte electric spot-welder capable
of welding duralumin-an entirely
new advance. The YIELDS have been
found to exceed rivets in strength
for the thicknesses. of metal en-
ployed. The metal can be welded
more quickly than it can be riveted
and the welded joints have the tre-
mendous advantage of presenting a
smooth surface to the air-a vital
factor in modern hish-speed air.
planes, In which exposed rivet heads
greatly reduce speed.
Commercial aviation is going to
profit by the war" Mr.. Martin said.
I'VE now know of improvements in
airplane efficiency which can be
made when this war pressure is re-
laxed which will give us new and
tremendously improved types Of
commercial airplanes within a few
years"
The present aircraft plants in the
United States are adequate for any
peacetime production which can be
foreseen at the present time, Mr..
Martin said. Any future expansion
of plants required to meet war orders
must be considered as war expansion
and charged off against the air.
planes as part of the war contracts,
he declared.
Tough Guy Of D. {. Police