Evening star. [volume] (Washington, D.C.) 1854-1972, 1928-07-15
CAPITAL MAN HOLDS IMPORTANT
POST IN AIR SAFETY CONTROL
c. L. 0fenstein Passes on All
Plans for New Passenger
Planes.
Commerce Department En-
uineer's Staff Checks on
Equipment.

II has fallen to the lot of Washing
tonian to occupy one of the most i'm
portant duties involving the develop
ment of civil and commercial aviation
! in America duty that possesses Moth
! Ing of the daring or spectacular, but
one that is bound hand and foot with
problems confronting the aeronautical
| engineer.
The occupant of this position is C. l..
! Ofenstein, a graduate Of Eastern High
School and the Massachusetts Institute
of Technology. an aeronautical engineer
Of IL years experience. chief of the en-
gineering section of the aeronauticS
branch, Department of Commerce.
Briefly. his lob is to sec to it that every
/ airplane manufactured for public con-
sumption is structurally sound; will not
fall apart in fight and kill the unsus-
pecting passengers.
The only way this can be accom-
plished is at the source. The time has
passed where an ambitious young man
with a mechanical leaning can uecIue
10 60 in for the manufacture OF air
planes; build crate in his woodshed
and sell it as an airplane to some one
who plans to make living by carrying
passengers Tor nIre.
All Must Be Approved.
Under the provisions of the air COM
merce act every airplane manufactured
for commercial purposes must bear the
approval of the Department of Com
merce, and once this approval Is
stamped on the airplane 1t Is guaran-
tee to the public that the craft Is safe
and sound, provided that the manu-
facturer carries out his part OF the bar
gain by building the plane according to
the approved blue prints and including
the specified material. To this end
however. the engineers and inspectors
are on the job and few Ii any de-
partures from the Government require
ments 60 by unnoticed.
There are certain minimum technical
requirements for commercial airplane
design that must be complied with be-
fore the manufacturer can hope to turn
the planes out at a profit to himself.
Thees requirements deal with the ability
Of the plane TO support certain loads IN
fight and to embody in its construction
certain grades of materials. For e%-
ample, the wings Of an ordinary COM
mercial airplane must be designed TO
carry from four and half to eight
times the total weight OF the entire ar.
plane--f they do not, what margin OF
When q new airplane is projected for
commercial production designs and
stress analysis in duplicate must De
turned into Mr.. Ofenstein and his stan
of engineers for study and check. II
they discover a glazing error In the cal
culations at the ouSet further work on
the drawings is abandoned, as all other
findings beyond that erroneous point
will be wrong. The design is sent back
70 its owner with the request that 1t DE
corrected or new stress analyses made.
Mr., Ofenstein or any OF his engineers
are unable to work out the erroneous
portions, as this would bring the FED
eTal Government into the design OF
commercial product.
Many Errors Found.
To date there have been 40 atrplanes
issued the approved type certincatss
and in 80 Of them, errors both great
and small were found In the preliminary
technical data.
| I'VE have to be on the alert every
minute and cannot afford to let any
thing slip by" Mr.. Ofenstein explained
IF we took the designers word for his
drawing that 1t was all right and the
planes built from that design began 70
fall apart In the air for no cause at all,
the approved type certificate from
then on would not be worth the paper
1t is printed on"
The minimum requirements for the
strength of an airplane and its ability
to Withstand certain heavy loads that
are brought on Its wings. fuselage, con-
troll surfaces, engine mounts, control
system and landing gear, is fixed by
the Department with the idea that that
plane is engaged In commercial pursuits
carrying passengers for example-and
hence its flying should consist OF taking
Of, flying level to the point Of destira-
ton and landing. Stunning Is not per-
mitted with passengers for hire and, 1t
is held, any pilot who has qualified for
a Federal license, knows that light COM
mercial ships when stunted violently
and with heavy lead aboard Is likely
TO develop structural failure.
Military planes OF the. pursuit ano
fighting type are built with load
factor ef IL times the weight of the
plane, meaning that the wings, although
designed to support the actual weight Of
the rest Of the craft, can. in an emer-
gency. stand up under IL times the
weight Of those parts. But as COM
mercisl. craft are not supposed to be
subjected to the stresses and strains
imposed upon military airplanes. the
load factor Is permitted to be much
less.
Engineers Watch Construction.
Once the design Of an airplane sub
n1itted Is approved, the manufacturer
begins construction and an engineer
visits his factory. closely supervising the
method OF building and the materials
placed in the plane. Frequently the
| inspectors have found methods of con-
struction they did not approve and upon
| further investigation found that the
! builder knew no other method. And
lust as frequently the inspector has
suggested the proper method, giving
valuable information that had 1t been
| lacking. might have cost some innocent
| lives
| When the plane Is completed, IL is
| weighed, and the weight OF the plane