Evening star. [volume] (Washington, D.C.) 1854-1972, 1926-07-05
HOOVER MAY ORDER.
RADIOS ON PLANES.
Commercial Aircraft Likely
to Benefit as Much Thereby
as Does Shipping.
BY CARL H. BUTMAN.

BY CARL III. BUTMAN.
Radio communication will soon be.
come as great boon to aerial navi-
cation, as 1t is to marine navigation
/ today, and it is very likely that radio
passenger-carrying aircraft, just as
it is now required on all sea craft.
| These are the opinions OF leading
| radio and aeronautioal experts of the
Government and commercial organi-
| cations.
The Air Commerce Act provides
that the Government airways be
equipped with radio transmitters for
furnishing the pilots with necessary
data on flying and field conditions as
well as their bearings. 1t is obvious
that Secretary Hoover's Forthcoming
flying regulations will require receiv-
ing equipment on commercial planes,
SO that they may receive this infor-
nation, and eventually small trans
hitting sets will be needed on all air
craft.
While radio communication with
airplanes has been in use in the Army
and Naval Air Services for several
years. 1t is by no means perfected.
nor is the more recent adaptation of
marine radio directional apparatus
exactly suitable for aerial navigation.
Governmental scientists are, however.
working on practical adaptations for
installation along the national air.
ways, and in the commercial planes.
Difficulties Are Obvious.
Some of the difficulties Of adopting
radio to aircraft are obvious, Heavy
and bulky radio apparatus cannot be
carried; neither the long nor the very
short-wave lengths seem suitable for
various reasons, and due to the speed
or aircraft the use Of an ordinary
martne-type direction finder aboard is
not feasible. 1t is being found diff
cult to fit the necessary aircraft radio
operating channels into the small
spaces left open in the already we'll
utilized radio spectrum
A channel between the broadcast
band and the ship distress channel is
allocated for regular aircraft work
that is between ground and aircraft
This band is between 545 and 500
meters, although another channel be-
tween 100 and 1876 meters Is also
assigned for aircraft use. Besides
| these channels it is possible, experts
state, that much shorter wave lengths
can eventually be used in air-radio
work, which will probably make for
economies in both weight and space
as well as power and length Of trans
hitting antenna. Eventually the long
trailing antenna used by most
radio work from airplanes may be
| eliminated
Other very important work being
carried on Is in perfecting the Army
radio beacon which has been operated
successfully for some time at McCook
Field, near Dayton. Ohio. The main
object Of the beacon service is to en-
able a pilot to know when he Is fol-
| lowing the direct air route toward or
away from it. This is necessary when
| navigating the air in either fog or
darkness 1t does away with the
necessity of carrying q radio compass
in an airplar 8. which is difficult for
a lone flyer to operate and also bulky.
Army Afrway System.
The Army Airway system now in
operation at McCook Field transmits
two distinct radio signals which are
directional and which require for re-
ception nothing but a standard radio
receiver in the airplane. One radio
signal is a dash, followed by a dot.
while the other is dor and then a
dash. Both are transmitted on 1850
meters, a governmental beacon chan
mel. When the plane Is directed
toward the source Of these signals or
directly away from them, the sounds
combine into a series Of dashes, but
if the plane Is deviated appreciably to
either side Of the course. one of them
becomes more distinct than the other.
II the dash-dot series is heard the
pilot knows he is off toward the left
side, and If the other signal is heard he
is veering toward the right. A demon
stration of this system with a model
was given recently by representatives
Of the Bureau of Standards. who also
explained that means of making the
signals visible to the pilot were
thought practical. The pilot, 1t was
pointed out. need not constantly listen
in for these audible signals, but merely
every 20 minutes or SO. in order to
check his direction or his compass
bearing. In the meantime. by throw
ing a switch he may shift his ears,
so to speak, to the communication
band around $50 meters to pick up
weather and field reports or orders for
landings.
This system, pronounced most
practical and quite necessary for long
distance or transcontinental flying.
will be installed on one Of the air mail
routes very soon for a final test and
will eventually be adopted over the
entire national airway system, 1t Is
believed. Over route Of 500 miles
it is probable that two directional bea-
cons, one at either end Of the route,
would serve. Ordinarily the signals
carry reliably for about $50 miles.
On an air route twice that length in
termediate radio beaeons would be re.
CURED
Other Aids Being Studied.
Several other forms Of radio aids
for air navigation are now being
studied and developed by experts of
the Government. Among them Is a
field locator, the purpose Of which Is
to enable the pilot to know when he
is over his landing field. and the other
method of ascertaining his height
from the ground. Both these systems
are intended to serve in darkness and
bad weather, but neither Is believed
adequate enough to permit dispensing
with guiding light beacons along the
routes, or field landing lights.
Whether radio communication be.
tween flying fields will be found neces-
| sary is a question. as yet undecided.
Between land stations and fields, tele-
graph and telephone lines can be used,
and 1t would seem practical to keep
the air as free from interfering radio
messages as possible, so that the pilots
and radio operators would not have
to cover more than few channels
The railway systems of the country