Evening star., 1937-03-12
PLANE VIBRATION
STRESSES STUDIED
Problem Features Joint
Aviation Convention Which
Closes Tonight.

Vibrational stresses in airplane en-
gines, propellerS and structures as a
source of structural failures and of
fatigue to crews and passengers were
among many problems of design and
construction taken under considera-
ton at joint convention of five ma
tionaI engineering and aeronautical
organizations now in progress at the
Mayflower Hotel
The convention will close tonight
with a dinner, at which the 1886 Manly
memorial medal, outstanding aviation
engineering award. will be presented
to Raymond w. Young, assistant en-
gineer, Wright Aeronautical Corp,
Paterson. N. j., for his work on air.
cooled radial aircraft engines.
Aroused to the full extent of the
dangers resulting from unchecked vi
bration in aircraft structures, the
more than 200 leading American air
plane designers, engineers, manufac-
turerS and transportation executives
attending the convention gave over
e complete session to the subject In
addition to the failure of metals sub
jected to severe and prolonged vibra-
ton, it was pointed out, vibration
creates internal frictional heat Suffi-
cient to char wooden and micarta
propellers.
Vibration Measuring Described.
Methods of measuring vibration in
flight were described by C. S. Draper
and G. P. Bentley of the Massachu-
setts Institute of Technology and H.
H. Willis, Sperry Gyroscope Co. The
vibration problem in airplane pro-
peller designing was discussed by F.
w. Caldwell, Hagmilton Standard
Propeller Co. Prof. Caldwell was
awarded the Collier trophy, most
coveted Of American aeronautical
awards, for his work on propellers.
The difference between octane num-
bers may mean little to the layman,
but to the airplane operator a differ
ence Of one number may mean an in
crease OF from 2 to cents per gallon
in the revenue earning power of
gasoline, it was pointed out by D. P.
Barnard Standard Oil Co. of Indiana.
Increased octane content is paving
the way to new aviation records and
increased operating efficiency, it is
held.
Yesterday afternoon the convention
delegates made an inspection trip
through the Bureau of Standards lab
oratories. They visited the refriger-
ated vacuum chamber, in which re-
searches are made on aircraft engines
under conditions Stimulating actual
flight to high attitudes and on fuels
and lubricants. They also visited
laboratories and wind tunnels where
studies Of vibration, fatigue failures
and aerodynamics are carried on.
Shown Foreign Fixtures.
Last night the delegates were shown
motion pictures of wind tunnels and
aeronautical laboratories in Germany,
Italy and England. The films, shown
here for the first time, were prepared
for the Institute of the Aeronautical
Sciences and were explained by Mai.
Lester D. Gardner, former president
Of the Aeronautical Chamber Of Com
merce.
-Four sessions on practical aerody-
manic problems, aircraft design and
two on engines are being held today.
Arthur Mutt, Wright Aeronautical
Corp, will discuss European aviation
engines at tonight's closing banquet.
The Manly medal will be presented
to Mr.. Young by DR.. George w. Lewis,
research director of the National Ad-
visory Committee for Aeronautics
and recent Winenr of the Daniel Gug-
genheim aeronautic medal
Organizations participating in the
conference are the Washington Sec
ton, Society of Automotive Engineers;
American Society of Mechanical En-
sineers, the Aeronautical Chamber of
Commerce Of America, the Air Trans
port Association of America and the
Institute of the Aeronautical Sciences