Evening star. [volume] (Washington, D.C.) 1854-1972, 1930-04-20
ALTITUDE CHAMBER
NEEDED FOR TESTS
Dr.. Dickinson Cites Work
That Could Be Done With
Air-CooIed Types.

There is urgent need for the installa-
ton at the Bureau of Standards of an
| altitude chamber for the accurate test
ing of large air-cooled aircraft engines
under conditions encountered in flight
at various attitudes, DR.. H. G. Dlckln-
son, chief of the heat and power dlvl-
sion of the Bureau of Standards, told
members of the Standard Flying Club
at meeting during the past week.
The present altitude chamber, which
is suitable only for the testing OF mud
cooled engines, has been the scene OF
tests of vital Importance to the aero
nautical industry since it was designed
and constructed by DR.. Dickinson dur
ing the World War.
The laboratory for air-cooled engines
would differ from the present labora-
tory chiefly in having provisions within
the engine chamber for circulating air
at the high velocity required for cffi-
cient engine cooling.
Study Superchargers.
DR.. DickinSon's division now is con-
Quoting in the altitude chamber studies
of the performance of aircraft engine
superchargers and the performance OF
the engines under .supercharged condl-
tons at varying attitudes, he told mem
bers of the club,
In the present chamber, DR.. Dickin-
son said, it Is possible to analyze the
characteristics of water-cooled engines
with the utmost precision, the limit OF
error having been reduced to about
one-half of per cent. In this labora-
tory tests have been conducted for
many purposes, such as the perform
ance of various grades of gasoline at
different attitudes, behavior of oils I'M
der various conditions of altitude and
temperature, variation of horsepower
with altitude and temperature, Carbu-
retting conditions, radiator perform
ance, influence of water injection on
engine performance and the perform
ance of various specific types Of air
craft engines.
The altitude chamber is one of the
largest and most expensive pieces of
aeronautical equipment Ii the bureau,
but is regarded as one of tie most es-
sential to the aeronautical industry,
DR.. Dickinson regards its use Tor the
production of fundamental scientific
data as of ineStimable vaile 10 the
military and civilian branches of the
Government and to aeronautical engi-
neers and manufacturers.
Engines Behave Like Humans.
Aircraft engines behave much rs hui
man beings do when taken to higher
attitudes, DR.. Dickinson pointed out.
The weight of air, which amounts to
Is pounds per square inch at sea level,
decreases to about pounds per square
inch at 1900 feet and to only pounds
at 10000 feet, or less than ore-third
that at sea level. At the same time
constantly lower temperatures are en-
countered until at 10000 feet the tenn
perature is as low as Al degrees below
zero, Dr. Dickinson pointed out.
It is unsatisfactory to make scientific
tests of the various phases of engine
performance at attitudes in actual flight,
and is just as unsatisfactory to take the
engines, with necessary test equipment
and personnel. up to the top OF some
lofty mountain, DR.. Dickinson said,
though when the first Liberty engine
was made for use in the World War 1t
was taken to the top of Pixies Peak for
an altitude test.
This procedure was entirely imprac-
ticable and expensive and gave results
at only one altitude" DR.. Dickinson
said. TT was suggested by the men,
bers of the Interallied Commission
visiting the United States shortly after
our entrance into the war that some
adequate means of studying the pc
havior OF aircraft engines at varying
attitudes be developed"
DR.. S. w. Stratton, then director OF
the Bureau of Standards. placed DR..
Dickinson in charge of the designing
and construction of a laboratory to meet
the suggestion of the commission. The
present altitude chamber was the result.
This chamber is room Is feet long, z
feet wide and feet high, built with
strongly reinforced concrete walls
capable of carrying loads of at least one
ton per square foot to resist nelng
crushed by the force of atmospheric
pressure as the air was exhausted from
the chamber by pumps.
u. S. Is Research Leader.
The United States, DR.. Dickinson
said, is the only country in the world
which has conducted consistent research
over a period of years in the matter OF
high altitude performances of aircraft
engines by this means. Germany had
small altitude chamber during the
war, but it probably was destroyed
after the armistice, he said. Italy also
had a very small chamber of this sort.
In 1928, he~said, English engineers de-
signed a small test chamber of cast
iron or steel, although, so far as is
known, it never has been used as has
the one at the Bureau of Standards.
1t is understood that Japan is building
an adequate altitude chamber of fairly
large dimensions, DR.. Dickinson said
| The Fiat Co. of Italy expects to build
one soon in cooperation with the
italian government.
The Standard Flying Club had as its
guests at DR.. Dickinson's lecture Wing
Comdr. Paolo Sbernadori of the italian
Embassy and Mrs. Lyle B. Steever
aaropouticaI diractOr of the aviation
section of the Women's City Club.