Matter of Fuel Consumption.
Taking the case in which the wind had a speed equal
to half that of the aeroplane, Mr. Lanchester said that
for a given journey out and home, down wind and back,
the aeroplane would require 30 per cent more fuel than
if the trip were made in still air; while if the journey
was made at right angles to the direction of the wind
the fuel needed would be 15 per cent more than in a
calm. This 30 per cent extra was quite a heavy enough
addition to the fuel; and to secure even this figure it
was necessary that the aeroplane should have a speed of
twice that of the maximum wind in which it was desired
to operate the machine. Again, as stated in the last
lecture, to insure the automatic stability of the machine
it was necessary that the aeroplane speed should be
largely in excess of that of the gusts of wind liable to
be encountered.
[Description: Black and white illustration: Four-part diagram.]