Evening star., 1921-09-15
STANDARD TERMS OF THE AIR
ORDERED FOR ARMY AND NAVY
Officers Of Two Air Services to Be Re.
quired in Future to Use Prescribed
Nomenclature.

| Standard aeronautical terms. de-
vised and compiled by the national
advisory committee fer eeronautics.
have been officially prescribed for use
IN the Army and Navy. Hereafter.
the new order states. the officers of
the two air services will use the reg
ulation nomenclature. -
For some time, aerial experts point
OUT laymen have been calling any
thing that traverses the air an "air-
ship" whereas the word aircraft"
| should be employed. They say that
ships. or lighter -than-air craft. are
constantly being termed "blimps,"
| slang word, now obsolete, but origi-
nally used to designate q non-rigid
airship driven by an engine installed
in an airplane fuselage :iung beneath
has often been misused in referring
to a seaplane. "HydroplaneH desig-
mates a sea sled, which planes on the
surface of the water. but does not
take the air. An airplane has been
called an aero" which, it is ,es, ss,
a water" The words "aeroplane."
''hydroplane" and "dirigible" have
been done away with and "airplane,
"seaplane" and 'airship" have taken
their places.
Kinds Of Aircraft.
| According to the recent published
report Of the national advisory COM
mittee, aircraft constitutes any
form Of craft designed to navigate the
air and is divided into "aerostats'' and
| "airplanes." Aerostats comprise light
er-than-air craft. embodying a con-
tainer filled with q gas lighter than
air. such as hydrogen; and sus-
"airships" and balloons"
Tha word "ai-plane" is now used to
| designate craft heavier than air. OBJ
| tanning their support from the action
| Of the air on the wings and driven
| through the air by screw propellers.
Tractors" are airplanes having their
propellers in front; 'pushers" hav-
ing them in the rear. Usually air
planes are equipped for land work
with wheeled landing gear. but when
boat or pontoon. the term "seaplane"
Is used.
"Airships," as the craft formerly
known as lighter than air are now
called. are divided into three types
rigid" whose form is maintained
bag or envelope: "non-rigid." whose
envelope is Kept taut by the pressure
of the contained gas. and semi
rigid" maintained by a rigid or
jointed keel and also by gas pres
sure. These three types are all pro.
PEELED by gas engines located in hull
or car or in individual engine houses
suspended below the supporting en-
velope. and controlled by means Of
rudders and fins.
the aerostat class. have no power
plants or means Of controlling their
horizontal flight. They include free
or flight balloons Of the old style
spherical type: captive" secured by
a cable to the earth; "barrage." cap
aerial barrage against airplane at
tacks; kite" elongated captive bal
Icons. such as the Caquot observation
balloon. which has tail fins to keep 1t
headed into the wind: nurse"
small. heavily fabricated balloon used
looms: and pilot" and sounding" bal
Icons. employed in securing meteoro-
logical data.
Heavier-Than Air Types.
!, The heavier-than-air types Of air
craft. now officially termed air
planes" are divided into several
classes. according to the number OF
superimposed. namely. monoplanes,
biplanes. triplanes and multiplanes.
There is also the Langley type of air.
plane. which is still called the tan
dem." from the arrangement Of its
double set Of wings on approximately
"seaplanes," airplanes designed to
rise from or alight on the water. are
classified in two groups-"boat sea-
planes" having a central hull not un-
like a boat: ana "aoat aat..s seaplanes; az Lane -
more floats or pontoons.
! Terms Employed.
stood terms are the following:
Aeronaut-The pilot of an aerostat
| (airship or balcony
Airdrome-A landing field equipped
with hangers and shops.
Aviator-The operator or pilot OF
lplanes and seaplanes.
Bank--To incline q plane literally
in turning to prevent skidding.
Ceiling-Maximum height to which
ruselageEsody Of an airpiane. in.
cluding passenger seats.
Glider-An airplane without a
power plant
Heliocopter-An aircraft deriving
its support not from wings. but the
Nacelle-Inclosure for passengers
or engines, but, unlike the fuselage
1t has no tail unit.
Ornithopter-An aircraft deriving 1t.
support and power from tapping
wings.
Pancake-To land by an airplan,
by leveling Oft higher from ths
ground than normal, causing it t.
stall and descend nearly vertically
Side slipping-Sliding on a banl
toward the ground.
Skids-Runners used with landing
gear. also on lower wing tips, as {
protection.
skiddinE-Sliding sidewise ava!
from the ground on . bank: opposit,
to slipping.
Soar-To fly on q level withou
power.
spin-An aerial maneuver in whicl