The sun., 1918-11-16
RYAN TELLS SECRET
OF AIRPLANE PHONE
Method Of Radio Communities
ton, Guarded During War,
Known Early in 1917.
COL. CULVER IS INVENTOR
System Which Bafflcd Ger
mans Perfected With Aid Of
e. J. Simon of New York.

One OF tho secrets OF the war was
released yesterday by John d. Ryan.
Director OF Aircraft Production. He
said that American pilots lighting In
France were directed by their squadron
commanders, who talked into the trans
mitter of a wireless telephone But the
fact that radio communication has been
perfected by Americans 80 that no
motor. no propeller, IL too loud to drown
out the human Voice that vbrates
through the ether into the ear of the
airplane pilot is not quite as much OF
a secret as Mr.. Ryan supposes.
The man who perfected this device,
who adapted the wireless telephone
to the airplane and gave the Americans
a wonderful advantage over the puzzled
German aviators, IL Col. Clarence c.
Culver, U. s. A, now stationed In WASH
ington. He has been working on 1t for
ten years AS long ago as February I.
1917. II was publicly announced from
San Diego, Cal, that Culver, then
Captain. had supervised a successful test
Of radiOtelephonic communication be-
tween a military plane in flight and a
land station.
>Rysn Tells of Device.
In making his announcement yester-
day regarding the use Of the wireless
telephone on the western front up to the
M nent the armistice was signed Mr..
Ryan said:
There are some details concerning II
which we cannot discuss yet but the
radio devices worked out during months
OF experiment went into actual service
some weeks ago. I have myself. stand
ing on the ground. given orders 10 a
squadron flying in the air and watched
them mannuvre accordingly. The trans
mission Of tho voice is clear enough TO
be heard distinctly through tho sound of
the airplane motor. II is in every way
satisfactory"
Mr.. Ryan said he could not discuss the
distances over which the radio telephone
has worked but they are known to be "A
matter Of several miles. II was said In
Washington that the Germans got scne
inkling OF what the Americans were do
ing just before hostilities ceased.
Col. Culver when a Lieutenant was
an observer Of the great aviation meet
at Belmont Park in 1910. He was one
of the first to appreciate the possibilities
of radio conversation from plane to
plane and from ground to plane. He
went to work on the problem. He and
p. J. Simon, a radio engineer OF New
York. Jointly directed the test held In
San Diego r. year and nine months ago.
Tests Prove a Success.
A newspaper despatch, published OH
the following day. said:
Flying at an altitude of 500 feet in
a tractor biplane piloted by Capt Her
bert Dargue, Capt. Culver succeeded In
transmitting several verbal messages a
distance of approximately three miles
Capt. Culver's voice came floating out
of the blue sky as clear and distinct as
the receiving room.
within the next ten days Capt. Gull
yer and Mr.. Simon expect to have little
difficulty in engaging in extended con-
versations while flying in two distinct
airplanes many miles apart. The War
Department has set aside two Martin
military tractors for radio telephone eX-
Fermentation"
The flfty-three airplanes which per-
formed simultaneous evolutions as the
closing spectacle of the army meet ut
Belmont Park, October 26. were directed
from the ground by wireless telephone.
Only a few OF the spectators knew this.
Most OF them supposed the pilots were
stunning" In obedience to signalling