New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1919-02-09
ut <VER since the beginning OF
r. Issoudun flying field" writes
- Lieutenant Joyce, airdrome

expert, in "'Plane News,
the air service paper of the A.
E. F., published in France, "even as
far back as the first flights of Wilbur
Wright, the question as to whether wind
has any effect on the stability of plane
has come up from time to time, and has
been argued both pro and con by expe-
rienced and inexperienced pilots"
In the article at hand Lieutenant
Joyce endeavors to explain both sides of
the question, and, as it develops, in
manner to prove both theories correct.
To begin with
"the theoretical side is easily proven by
diagram and be checked by actually
taking plane up and observing it's per-
Torrance under similar conditions.
"The practical arguments are brought
about by q psychological effect that the
average pilot does not take into considera-
ton, that is, the difference in motion rela-
tive to the wind and that with the ground.
"The action of plane under varying
conditions can best be described with the
aid Of diagram as shown below, and the
paths of fight designated are relative to
the ground, as we cannot disregard the
effect of mother earth. Some pilots have
tried, but none seems to get away success
fully.
"To proceed to the problem. Assume
condition where there is no wind and the
pilot is travelling on the line C in
northerly direction at speed represented
graphically by B in q unit of time and
wishes to land along the line M. With
the required amount of bank and rudder
the plane will describe a semicircle X
and be headed toward M ready to land
"Now consider wind blowing in north
erly direction equal to the velocity of the
plane and that velocity represented graph
icaly by B. The planes velocity being
C, the resultant action in unit of time
at the beginning Of the maneuvre would
be A c. With the same amount of bank
and rudder as that used under condition
where there is no wind, in the next unit Of
time the planes position will be D prime
and not D, and through consecutive inter
walls E prime F prime, prime, H prime,
J prime, instead of E, F, G, H, X and l..
"1n the second unit of time from C, as
rudder and bank brought into play,
due to the planes motion through the pre-
vailing wind, it will have westward COM
ponent Of c and northerly component
Of X D. With the velocity of the wind
added, the resultant position of the plane
will be D prime
"In the next unit of time, due to the
planes given amount of bank and rudder,
its westerly component will be D X, which
will have it's effect, not from D, but
prime, and its northerly component equal
to E X plus the velocity Of the wind, bring
ing the plane into position of prime
"The reader can, by little study, easily
follow the successive stages of the planes
movement throughout the length of time
necessary to turn at $50 degrees, facing into
the wind at K, where at this point it will
have no velocity relative to the ground in
any direction.
"The curve c o represents the path of
plane when the wind velocity is one-half
Of its own and one can see that the
point at which the plane has no north
erly or southerly motion on the various
curves will pass from X to z and finally F,
according to the wind velocity.
when there is a condition of no wind it
will be seen that at the plane is travel
ling over the earth in direction the same
as that in which the longitudinal axis is
pointing. AS wind comes into effect, the mo-
ton of the plane at the central points Of
the curves will not be in line with the
longitudinal axis, but more or less side
wise. 1t is at this point when turning with
the wind that new pilot, who is a mechan-
ical fier and who has not learned to fly by
feel observing his plane passing over the
ground sidewise, assumes that he is skid
ding and puts on more bank. This we all
know is the correct thing to do for skid
or else rudder into it, but, as the plane was
not skdding relative to the wind in which
it was travelling and in perfect stability.
such movements would cause a sde-slip and
possibly a fatal accident if close to the
ground.
"ln plane where there is lots of motor
such q move would not be so marked. but
with types such as the Curtiss or Caudron.
in which you have to nose down on turn.
any such action would be distinctly notice
able.
when turning against the wind plane
will seem to slip instead of skid and the
inexperienced pilot will make the mistake