Evening star. [volume] (Washington, D.C.) 1854-1972, 1929-07-07
SAFER A|RPLANES
ASSURED BY RULES
Department OF Commerce
Provides More Rigidly
for AirWorthineSS.

More rigorous standards Of inspec-
ton, to insure safer airplanes In the
United States, are taken in the new
Department of Commerce "airworth-
mess" requirements, which have just
been issued. The new code sets up
stricter standards for the safety of vital
parts of aircraft.
An analysis OF the requirements,
made by the Aeronautical Chamber Of
Commerce, shows that 80 specific
changes have been made In the code
of airworthiness requirements. This is
the code followed by American air.
plane manufacturers to enable them
to comply with requirements for ap-
proved type certificates for their planes
before they may be sold to the public.
Advance copies of the new code have
been prepared by the chamber and sent
to its members, including approximate
ly 95 per cent of the airplane manu-
facturers In the United States, 1t was
learned today.
Requires Loading Tests.
The Department of Commerce, In its
efforts to bring about further strength
enlng OF airplane structures, will re-
qulre manufacturers to demonstrate by
loading tests the strength of all control
surfaces and control systems and the
shock absorbing qualities of landing
gears on their planes. Such tests have
not been required in the past
The new code requires that speci-
mems OF all the wood members used in
alrplane construction must be- loaded
to the point of destruction and samples
OF the parts that fail shall be analyzed
TO determine their physical properties
and the cause of failure.
IL Is further required that all cabin
planes must have at least one exit for
each six persons carried. Present rules
require only two exits, regardless of the
number OF passengers carried Detailed
specifications for all openings and exits
are included in the code.
Greater attention is paid to engine
mountings and to means of preventing
engine overlooking. The former made
quate regulations for installation Of
alrplane engines have been consider
ably expanded and now include detailed
instructions for various types OF mount
lngs TO insure the highest possible type
OF construction.
Propeller CIearances.
AS further safety measure. the new
code orders that propeller clearance
above the ground be increased from
minimum of 6 inches to inches for
landplanes. Clearance above water for
cS0FA0hC PlOPEllClo IIluSJ Dp at IeshSt 10
inches. Propellers must be so designed
and adjusted, the new code stipulates,
that they will limit the engine speed
to los per cent of the official rated
speed at full throttle in level fight.
Performance and fight test specifica-
tons have been amplified. and the new
code describes in considerable detail
the procedure to be followed by in
Spectors for the aeronautics branch of
the Department Of Commerce
The code also seeks to bring about
strengthening of airplane wings. 1t is
provided that the relative efficiency of
biplane wings must be determined from
rational formulate, instead of from the
rather vague curves formerly specified.
Methods of calculating air loads and
dead weight for wings which are ia
pered in thickness have been altered to
comply with the latest facts known to
aeronautical engineers.
The introduction of glider building
and flying in the United States receives
recognition in the code as a special
branch of aviation. A new paragraph
has been devoted to specifications for
glider construction.