Evening star., 1927-10-12
Flying With Gen. Patrick
By Mai. Gen. Mason NJ. Patrick
Chief of the Army Air Corps


cockpit. Our gaze first falls upon the
| instrument board, which is directly In
front of and facing the pilot. Many
of the instruments are similar to those
seen in an automobile.
The power plant of an airplane, Ike
the automobile, is gasoline engine,
and requires the same instruments to
indicate oil pressure, temperature, fueI
pressure, etc, besides the customary
/ ignition switches and electrical instru'
ments. In addition to these there are
several instruments peculiar to ar
craft. One is the air speed meter. OF
which previous mention has been
made.
Since an airplane in fight has no
contact with the ground. its speed
with reference thereto is not measur'
Table by means of speedometer such
as is used in the automobile. 1t has
contact only with the air through
which it is passing. The air speed
meter, therefore, is substituted for
the speedometer and indicates the
speed of the plane through the air.
Since the air seldom is at rest, 1t can
be seen readily that air speed usually
does not indicate speed with reference
to the ground. When flying with the
wind the ground speed of the plane,
for all practical purposes, is its air
speed plus the velocity of the wind; or,
conversely, if flying into the wind, its
speed is decreased by the velocity OF
the wind.
Coin New Words.
A cross wind tends to drift a plane
off it's normal path, and in order to
maintain straight course between
two points it is necessary to point the
plane into the wind at an angle suff1-
cient to compensate for the drift. The
resultant of the two forces (the velo-
city of the wind and the speed of the
plane) then becomes the desired direc-
ton of the motion with reference to
the ground. To explain this action the
nautical term Grabbing" has been
borrowed.
h The development of aviation as a
medium of transportation has resulted
in the coming of a number of new
words. Among them is "avigation,"
which is derived from the two Latin
words avis and agere, and means ito
go as a bird" 1t is analogous to the
nautical term navigation"
A necessary aid to avigation is the
compass, the dial of which appears
among the instruments in front of
the pilot. The compass in most COM
mon use is of the floating dial mag
'netic type. This type of compass is
not, for various reasons, entirely sat
isfactory for aerial purposes, and re-
: cent experiments have developed the
: earth inductor type, which played such
a prominent part in the successful
: transoceanic flights during the past
Summer.
Other instruments Used.
While for ordinary purposes the
: skilled pilot is able to estimate the
height at which he is flying with a
fair degree of accuracy, there are
, many instances, particularly in mill.
tary aviation, which require a more
, accurate method of measuring alti-
tude. The instrument employed for
this purpose IS called an ''altimeter." "
Almost every one is more or less IA
, miliar with he baromeer, which
measures the weight of the atmo-
} sphere. The altimeter merely is an
aneroid barometer, having a dial
graduated in feet of altitude rather
than in pounds per square inch.
AS an aircraft ascends the density,
; and therefore the weight, Of the at
mosphere surrounding it decreases, re-
sulting in decreased barometric pres
sure, which causes a change in the
position of the pointer on the dial of
the instrument. The recording alti-
meter used in altitude tests likewise
is similar to the recording barograph
In common use by meteorologists, or
weather forecasters.
Still other instruments which attract
our attention are the ''taehometer''
and. the ''bank-and-turn Indicator" ;"
! The former merely represents the APP
plication Of the well known revolu-
tion-counter principle. which not only
counts the revolutions of the engine
crankshaft but also registers, by
means Of dial and pointer, the num-
Der per minute. 1t involves some
what the same principles as those of
an automobile speedometer, and regis
ter1 revolutions per minute rather than
miles per hour. The "bank-and.turn
indicator" is combination of the
principle CT the spirit level, which in
dicates when the plane is laterally off
even keel, and gyrostatic mechan-
ism which indicates the direction in
which the plane is turning, if at all.
Levers Easily Reached.
Leaving the instrument board, we
now direct our gaze farther downward
in the cockpit. On the left, within
easy reach of the pilot, are three small
levers, two projecting upward and one
downward. One of the former is the
throttle; the other is the spark con-
troll, and the latter, commonly called
the altitude adjustment" regulates
the mixture of air and gasoline in the
carburetor. In the rarefied atmo-
sphere aloft the proportion of air to
gasoline may be increased in order to
obtain greater engine efficiency with
a reduction in fuel consumption.
In the center of the cockpit, pro-
jecting vertically and directly in front
of the pilot, is metal shaft or lever,
usually with a rubber hand-grip cover.
Ing the upper end. Upon this rests
the pilots hand. This mechanism is
the "joy stick" 1t is connected by
cables to the ailerons and the NOV.
able portions of the horizontal tail sur
faces. By means of this lever the
longitudinal and lateral controls Of the
plane are operated.
The rudder control in most common
use consists Of wood or metal bar
with stirrups or footrests at both
ends, located near the floor and at
the front of the cockpit. 1t operates
on pivot in the center. From each
end of this bar wire cables extend
backward through the fuselage to the
rudder, thereby enabling the pilot to
operate the rudder by movement of