Evening star. [volume] (Washington, D.C.) 1854-1972, 1929-02-17
NEW COWL|NG AID
TO PLANE SAFETY
Also Causes Economy o.
Operation by Decreasing
Amount of Fuel Used.

Greater speed, safety and economy o
operation and longer cruising range
are possible with multi-motored air
planes which are equipped with the new
cowling for air-cooled motors recent.
perfected by the National Advisor,
Committee for Aeronautics, the com
mittee stated in the second section o.
Its cowling report. just issued.
Although the cowling has beer
adapted with marked success to single.
motored planes, its effect on multi.
motored planes is even more pro.
nounced, the committee reported. The
drag of air resistance of the two out
board motors on tri-motored airplane
without cowling is more than twice thai
Of the engine and entire fuselage of g
single-motored plane, tests made by the
committee have revealed.
Hawks Tested Design.
The increased efficiency of a single
motored plane using the new cowling
was indicated by the committees first
report to be from Is to 20 per cent
When given its first practical test re-
Gently on the record-breaking coast-to-
coast flight of Capt. Frank M. Hawks
the new cowling was created with add
ing 90 miles an hour to the speed OF
his Lockheed monoplane
AS the cowling principle is more ef-
4ective when applied to small bodies
such as the engine nacelleS of multi
engined planes, the increased efficiency
of three-motored planes equipped with
the cowling is indicated by the new re-
port to be from 20 to Is per cent.
This latest development" the COM
mittee reported, 'is of greater impor-
lance when it is realized that the next
big step in the development of COM
mercial aviation will be the develop
ment of large airplanes for passenger
cir lines.
1.-THE use of the N. A. c. A. cowling
on such airplane will not only permit
higher operating speeds and better
maintenance of schedules but will also
reduce the cost by decreasing the
power required and thus vii go long
way toward facilitating the growth of
air passenger traffic In the United
States"
Fuel Saving Estimated.
The committee estimates that tri-
motored plane equipped with cowling
for the three motors will be able to
AIC1cdSC Lbc hfctdSC CL uLSALlS SPCC0 1iOIil
100 miles an hour to 125 miles or to
maintain its 100-mile rate with the
motors throttled down and consuming
20 to IS per cent less fuel, representing
a saving of about 81 gallons of gasoline
per hour for the average tri-motored
passenger plane. At the same time
the maximum flying range with the
same amount of fuel will be increased
90 to Is per cent.
Planes equipped with three 200-horse
power motors and capable of cruising
100 miles per hour committee experts
said, would have to be equipped with
three 400 horse power motors and
strengthened throughout to attain an
average cruising speed of 100 to 1875
miles per hour This change would
cc1s approxin ately $4,000. The same
rrg'llt3 could be obtained by adding
TIRE cowlinSs at a cost of about $25
ea-h.
Viewed from the standpoint of saftey
IN aght, the experts declared, it pro-
Vi les equally striking results. The
frcTg-n Of safety is greatly increased.
toy explain, because the cowling en-
si5l~s the plane to fly as well with only
ITO engines working as it can with all
ti,"9a in operation when the engines are
nc cowled.
It IS the effect of the cowling in
reducing the cost of operation and its
aiditicn to the margin of safety rather
then its contribution to speed and
range on which the experts rely to
stimulate the development of air
passenger lines.