May 1946 Radio News
Wax nostalgic about and learn from the history of early
electronics. See articles from
Radio & Television News, published 1919-1959. All copyrights hereby
News reports are full of features about the wave of radio controlled
(R/C) 'drones' terrorizing citizens with their often inexperienced
pilots navigating their camera-laden craft to peer into bedroom
windows, obtain 'birds-eye' views of sporting events, and to be
a general pain in the posterior to people trying to enjoy their
right to privacy and safety (except, of course,
unless it is the Government choosing to violate them). Incredible
advances in radio, navigation, and sensor systems has facilitated
a wide variety of very affordable multirotor
(the correct term, not 'drone') aircraft
that can literally fly themselves. For under
you can buy a GPS-guided multirotor that can be programmed to fly
to one or more waypoints and return to the launch location, with
range and flight duration limited only by battery capacity. Gimbaled,
remotely steerable cameras can snap photos or record video and either
store it onboard for later retrieval or wirelessly transmit the
images back to the operator. Platform stabilization is provided
by ultra-miniature, ultra-lightweight orientation and rate gyros
with precision and accuracy that could not have been realized even
two decades ago. Intelligent software practically negates the need
for an operator to do anything other than point the craft where
he/she wants it to go. Compare this to what was considered ground-breaking
remotely piloted aircraft technology in 1946.
Pilotless Plane Run by Radio
By S. R. Winters
The successful operation of aircraft by remote radio control
has been proven practical by the A.T.S.C.
Planes in the radio remote control of aircraft project,
developed by the Air Technical Service Command and Bell
Aircraft Corporation. Both are jet-propelled P-59 Airacomets
with the controlling flight station, the "mother" ship,
shown at the top.
Transforming a 20-year-old vision into an actuality, a pilotless
airplane is operated by a combination of factors involving the use
of radio and television. The jet-propelled plane, a P-59 Airacomet,
is remotely controlled either from a portable ground radio station,
mounted on a truck, or from a "flying radio station" in another
airplane which "mothers" the robot craft.
"Telemetering," a comparatively new term as applied to radio,
and only recently recognized officially by the Federal Communications
Commission, means that electronic apparatus installed on the pilotless
flying craft transmits to the ground radio station visual images
of the vibrations, accelerations, structural leads and strains,
and similar stresses encountered by the robot plane. This new telemetering
apparatus, designed by Princeton University, is concentrated in
the pilotless plane and ground radio station, the "mother" plane
being reserved for the exclusive function of controlling the "orphan"
craft which flies without any person aboard. The process of determining
structural strains and stresses, as well as other data from the
pilotless plane, involves the use of resistance units in measuring
the plane's performance electronically. Such information is fed,
in sequence, to the electronic transmitter at a rate of 1100 cycles
per second. This data is transmitted to the ground radio station
for reception by a radio receiver that unscrambles the jargon of
combined signals and then "siphons" them into separate. receiver
channels for graphic recording or visual observation, or both, on
a many-channeled oscillograph.
The television equipment on the pilotless plane, manufactured
by the Radio Corporation of America, serves a twofold purpose. One
unit visualizes the instrument panel on the robot airplane, thus
televising the behavior of the instruments during the plane's flight,
and this information is relayed to the operator of the ground radio
station. The second piece of television apparatus, installed in
the cabin of the plane without a human pilot, actually scans the
horizon as it would be seen if an honest-to-goodness pilot were
flying the machine and this vision of the horizon as viewed by the
"robot" is relayed to the operator of radio equipment in the motor
Three physical components of the radio remotely controlled
plane project developed by the Air Technical Service Command
and Bell Aircraft Corporation. Left to right. the panel
truck which operates the controlled, or robot plane and
incorporating telemetering and television equipment for
observation and recording of flight research data; the robot
plane and the controlling plane. Both aircraft are P-59s.
This experimental aircraft, joint brain-child of the Bell Aircraft
Corporation and the Air Technical Service Command, Wright Field,
Dayton, Ohio, is a preview of an imminent period of flight of commercial
airplanes through the combined factors of radio and television.
More than a year ago this writer forecast the imminence of the "all
electronic airplane" - a craft functioning solely by "electronic
fingers" rather than by the hands of a human pilot. Although the
Bell Aircraft Corporation is using this experimental jet-propelled
plane as a sort of "flying research laboratory" in assembling data
that might influence the flight behavior of a plane, the company
believes that remote control of aircraft by radio is impending,
both from a commercial and military viewpoint. Furthermore, by use
of this robot plane the risks of sacrificing human pilots in hazardous
flights at sonic and supersonic speeds are averted.
The successful flights of this radio-operated plane - since October,
1944, but until recently among the war-pigeoned secrets - are attributed
largely to a new concept of the autopilot - described as the "rate"
auto-pilot by Robert M. Stanley, chief engineer of the Bell Aircraft
Corporation. This novel gadget, automatic in performance, assures
control of a plane where the orthodox autopilot leaves off - and
it can function dependably when the craft is approaching a diving
Turbo jet-powered planes were chosen for the initial tests with
pilotless, radio-operated flying machines for several "down-to-earth"
reasons, namely, the absence of torque and vibration; their stability
even at the speed of sound; their efficiency in the stratosphere
or other high altitudes; and the stability they demonstrate when
landing by means of tricycle landing gear.
More about the new version of the autopilot - the "rate" autopilot
- which receives the lion's share of credit in realizing the aeronautical
engineer's dream of controlling aircraft solely through the means
of radio and television. Instead of the standard autopilot, controlled
by a gyroscope which spins about its vertical axis and is therefore
subject to "spilling" in violent maneuvers, the new type of autopilot
makes use of two rate-of-turn gyro instruments. One of these is
so arranged that the gyroscope's spin-axis is vertical as a means
of affording a way of sensing a change of pitch. The second gyro
device is rotated so as to place the gyroscope fore and aft, thus
providing a method for determining the rate of roll.
Radio controlled jet plane lands at Wright Field by remote
control. Either the "mother" plane. shown in flight, or
the truck ground station at right can control the plane.
Then, these two sensing gadgets - the "rate" and "displacement"
auto-pilots-are coupled in an electrical bridge, with their functions
being interchangeable. The "displacement" or orthodox autopilot
is answerable for maneuvers involving less than plus-or-minus 30
degrees change in pitch or plus-or-minus 45 degrees in roll. The
new version of autopilot - the "rate" mechanical pilot with its
spill-proof gyroscope, is answerable for any other maneuvers to
which an airplane may be subjected. The "flying radio laboratory,"
as well as the ground radio station, has a switch, handy on the
instrument panel, which permits of easy selection of the two autopilots.
Simultaneously, either or both of these mechanical pilots can be
governed from both air and ground radio stations,
A diminutive "joy" stick, functioning like the conventional control
stick on a standard airplane, is mounted on the usual stick in the
"mother" plane and another pigmy stick, a duplicate, appears on
the ground radio operator's chair. This small stick is secured to
a platform built on top of the radio-equipped motor truck. The movements
of these midget sticks are comparable to those of the conventional
"joy" stick. Moved forward, for example, the miniature stick prompts
the impulse that lowers the airplane's elevators, causing the radio-controlled
plane to dive; moved backward, the undersized stick prompts a climb,
and to the right or left, a turn of the airplane in either direction.
The throttle, flaps, landing gear, brakes, etc., of the radio-operated
plane are actuated by the usual servo motors, deriving their electrical
energy from circuits controlled by the radio receiver. Thus, by
coordinating these controls, the radio operators of the flight or
ground stations can put the robot through such actions as warm-up,
taxiing, take-off, climb, level flight, banks or turns, dives and
The operation of this radio or electronic airplane is dependent
upon novel and heretofore untried apparatus, with special and secret
radio parts, designed especially for Army Air Forces' Technical
Service Command, This radio equipment is as vital to the functioning
of the airplane television and telemetering equipment as are the
heart and lungs in the functioning of the human body. The incorporation
of high-frequency radio apparatus for voice communication is optional
rather than a requirement, we are told.
Posted March 5, 2015