Evening star. [volume] (Washington, D.C.) 1854-1972, 1931-10-18

hour, he pointed out. At the same
time, however, take-off and landing
speeds have grown so great that spe-
cial design and skill have become
necessary to prevent disaster. The
take-of speed of the Schneider racers
is above 100 miles an hour and they
are landed at far above this speed
Such speeds a few years ago would
have been virtually suicidal.
Another thing Schneider racing has
done is to improve the design of sea-
plane floats, bringing about suitable
compromise between the type that is
best for a float but bad as a source
of air resistance and the type that
pulls cleanly through the air but is
poor or the water.
Still another beneficial result has
been in the design of radiator sur
faces to carry off excess engine heat.
AS power has increased and airplane
size decreased it has become necessary
to convert the ship into something
akin to flying radiator, in which all
the wing surfaces and the top sides
of the floats are formed of a double
metal skin through which the hot
ing back into the motor. In addition,
motor oil must also be cooled in radi-
ators along the fuselage skin. The
equivalent of more than 1000 horse
power in heat units must be trans
ferred continuously to the air, and the
problem has just about exhausted the
capacity of a plane of the size used
in this years competitions.
Much Experimental Work.
The problem has been to provide
more cooling surfaces or to improve
the efficiency of those already used.
A great deal Of research work was
undertaken and the result was that the
oil-cooling system of 1929 had its eff
flciency increased by 40 per cent, Sir
Robert said.
There have been mass OF con-
flicting problems to solve, all of which
contributed much to the sum of aero
nautical knowledge. The mere carry
ing of fuel and oil and feeding them
to the motor was a severe problem. It
is easily perceived that an airplane
rounding turn at $40 miles per hour
will set up tremendous centrifugal
forces which easily might choke the
flow of oil and fuel to the motor If
Distribution OF fuel and Oil weight
had to be planned to take care of
the tremendous torque or twisting eff
feet of the highly pitched racing pro-
peller while taxing on the water
This torque has the effect of sinking
the lelC noaC ana raising the right
out OF water and, with an even diStri-
button Of weight, probably would turn
the plane over. This effect is coun-
teracted by carrying a bulk of the
fuel load in the right pontoon on the
water and by equalizing the weight
after the plane is in the air and the
effect Of torque is ironed out by wing
lift.
And so, the work which made pos
Sible the magnificent British Schneider
racers has resulted in better knowl-
edge of float designs. controls at high
speeds, propeller design. radiation, de-
sign Of fuel and oil systems and other
problems of aircraft design which may
be applied to aircraft design the world
over.
In addition. the competition has put
such premium on engine performance
that the British Rolls-Royce racing
motor. which before the 1929 races
was delivering 1928 horsepower. was In
1929 increased to 1000 horsepower and
in 1881. with further Improvements
and but trifling increase in weight,
was delivering 1900 horsepower with
total motor weight Of less than three
quarters Of a pound per horsepower
This degree of motor efficiency is little
short of astounding when compared
with any other type of man-made
power plant, the speaker declared.