Evening star. [volume] (Washington, D.C.) 1854-1972, 1929-03-24

wave length between 800 and 900
meters. to be allotted by the Radio
Commission.
Radio transmission will be restricted
to messages between ground stations
and planes or between planes. For
messages between ground stations a
tele-type system has been installed.
This system operates so that message
typed on q keyboard OF one tele-type
machine appears instantaneously on the
machines at all other stations on that
circuit.
The tele-type system will be used for
rapid and continuous ground COMMUNE
cations. especially in disseminating
weather reports. It will be employed
also for plane dispatching, ordering
plane movements, transmission OF re-
ports, reservation requests and inter-
company messages.
Mail planes Of the National Air
Transport system are operating between
New York and Cleveland on the radio
beacon beams from the Department Of
Commerce radio beacon stations at Had
ley Field, N. j.: Bellefonte, Pa, and
Cleveland Additional stations soon are
to be In operation on the Chicago
Cleveland division.
The radio beam on the Eastern di-
vision is broadcast by transmitters
known as eQui-signal beacons. The
pilot is guided by a series Of three
characteristic signals which tell him
whether he is on his course, or, If
| not. to which side he Is flying.
Weather reports are transmitted TO
the pilot through voice transmitters
from the ground stations to the plane
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wave length than the beacon signal
system. Ordinarily the pilot Is given
hourly weather reports, but, in event
Of a severe weather change ahead Of
him. the radio beacon can be inter-
rupted as a signal for him to tune
to the higher wave length to receive
voice transmission.
Pilot Has Two Controls.
The pilot has but two radio controls,
one a remote control tuning dial and
the other q volume control. At present
the pilot can only receive, but device
Is being perfected for two-way COM
munication, and all National Air Trans
port planes eventually will be equipped
with this type Of equipment.
In thick weather the pilot can de-
termine the proximity of an airport
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the narrowing path of the radio BEAM
This beam spreads sometimes to the
width Of two miles or more near the
end Of its effective path, but narrows
nearer its origin. The pilot Is able to
tell by the intensity Of the signals and
the narrowing of the effective path of
the beam when he is nearing the sta
| ton.
Further aid in locating the field is
given by a marker beacon which sends
out strong signal that can be heard
through the course signal. informing
the pilot that he is above the field
Between two airports equipped with
directional apparatus the pilot follows
the course indicated by the one he has
just left for about half the distance
to the next, when the beacon located
at the field toward which he Is headed
becomes effective and he follows its
converging beam through his receiving
set to his destination.
It Is planned to have directiona1
| radio beacon stations located at 200
| mile intervals over all the principal
airways, severe testing of the existing
system In all types of weather having
proved their reliability and value as
| an aid to aerial navigation.