Welcome to the RF Cafe Website

Search:                 | Sitemap

About RF Cafe | Homepage Archive

Kirt Blattenberger (KB3UON)

Advertise on RF Cafe (Advertisers)

RF Cafe Live Blog | Forums

Copyright 1999-2030

Electronics & RF | Mathematics

Physics & Mechanics | Quotes

Crosswords | Humor | Podcasts

Quizzes | Cogitations | Articles

Parts & Services | Videos

Radar Handbook | Cool Things

Selected Vintage Magazine Articles

Electronics World | Radio-Electronics | OFA

Radio & TV News | QST | Popular Science

Popular Mechanics | Radio-Craft | Electronics

Popular Electronics  | Mechanix Illustrated

Short Wave Craft | Saturday Evening Post

RF & Electronics Symbols for Visio & Office

RF & Electronics Stencils for Visio

RF Cascade Workbook | Espresso Workbook

Innovative Power Products Passive RF Products - RF Cafe

Windfreak Technologies Frequency Synthesizers - RF Cafe

PCB Directory (Manufacturers)

Anti-Plane-Collision Radar
March 1961 Radio-Electronics

March 1961 Radio-Electronics

March 1961 Radio-Electronics Cover - RF Cafe[Table of Contents]

Wax nostalgic about and learn from the history of early electronics. See articles from Radio-Electronics, published 1930-1988. All copyrights hereby acknowledged.

What a difference a punctuation mark can make, in this case a hyphen. If this 1961 Radio-Electronics magazine article had been titled "Anti-Plane Collision Radar" rather than "Anti-Plane-Collision Radar," the theme might seem to address a radar system biased against airplanes and desiring to promote collisions amongst them, rather than wanting a radar system designed to prevent collisions. In making his point, editor Hugo Gernsback uses as an example a recent (at the time) 1960 mid-air collision between a Douglas DC−8 (4-engine jet) and a Lockheed Super Constellation (4-engine propeller) which occurred over New York City. Another cited was a 1956 mid-air over the Grand Canyon, which also involved a Super Constellation and this time a Douglas DC-7 (4-engine propeller). Airborne collision avoidance systems (ACAS) have been incorporated into airborne radars for many decades, which act independently of ground-based collision avoidance systems. Mr. Gernsback's call (and those of many others) was answered.

... Up-to-Date Aircraft Safety Measures Are Needed Urgently ...

Anti-Plane-Collision Radar, March 1961 Radio-Electronics - RF CafeBy Hugo Gernsback, Editor

The tragic airplane disaster of Dec. 16, last, in which 134 persons were killed as a result of the collision of two airliners over New York, points up anew that present-day safety measures are fundamentally inadequate, particularly near our large metropolitan air centers.

More than 175 planes are often in the air together within a radius of 50 miles over New York City. By 1975, there will be over 350, according to a Federal study recently made.

Modern jets today fly at the rate of 550 miles an hour when cruising at full speed. Two jets on a collision course can thus approach each other at rates up to 1,100 miles per hour, or over 3 miles in 10 seconds. Even if the pilots see an oncoming plane, it is doubtful that they can prevent a full head-on or partial collision.

In a few years, jets now on the drawing boards will fly at 1,300 miles cruising speed. How will they be handled?

Today, jets approaching our airports must fly at a reduced speed of about 230 miles an hour, and are guided to the proper runway by the technicians of Federal Aviation Agency. The guiding is customarily by radio-phone from ground to plane. The tower operator literally talks the plane down. In an overcast and thick weather, the incoming plane also uses its electronic Instrument Landing System (ILS).

But last Dec. 16, when the two doomed planes were on a collision course and were fully alerted to their danger by ground personnel, one of the planes was some 11 miles off course and completely "blind" in the thick cloud overcast. Hence, even if the pilot did take evasive measures, he could not possibly have known whether he was heading out - or into - the danger course in the thick murk.

The obvious answer to this and similar situations is radar. We have commented on this over the years since 1951.*

After the 1956 two-plane collision over the Grand Canyon that took 128 lives, we said editorially, in Our May 1956 issue "Airplane Collision Control":

But a plane flies in a three-dimensional medium. Pilots have only a comparatively small angle within which to make visual observations. They cannot look behind them, far sideways or above, or below them at a steep angle in a heavy overcast. Hence the "visual control" is wholly academic and - under certain adverse weather conditions - absurd.

We also quote from our 1951 editorial (before the practical advent of the transistor):

"It should be possible in the meanwhile, however, to use a six-way modified - or sweep - radar installation, which need not weigh too much if miniature tubes and other miniature components are used. In this case, too, there would be several miniature screens which pilot or copilot could watch and see if another plane was approaching from any direction. When finally engineered, such a device will prevent many collisions. Such radar installations will be particularly advantageous during night flying and while flying in overcast weather when the visibility is extremely poor or nil."

What was meant here was two specialized steep angle sweep radars, one on top of the plane, one in the belly. Using two such radars, the pilots are enabled to see in six directions at once: east, west, north, south, below and above.

Weight and space requirements, once a serious handicap for commercial airplane radar, are no longer an insurmountable problem today, thanks to transistors and microminiaturization.

It is quite inexcusable to postpone the adoption of collision radars any longer - neither the cost nor technical difficulty can be given as valid reasons for delay. While radar installation on aircraft may not be a 100% solution and insurance against all collisions, it will certainly do away with a large proportion of midair crashes.

When we speak of radar, we should also mention the fact that not all radars function on radio waves. There is, for instance, the infrared or heat radar developed during the past several years by Aerojet-General Corp. It uses a rapidly rotating mirror which scans the sky for other planes. The mirror is sensitive to infrared heat rays from a distant airplane engine. It has an automatic warning instrument in the cockpit to alert the pilot that he is on a collision course. It also gives the range and bearing of the oncoming plane. Total weight of the new infrared radar is but 30 lb.

How serious the density of our aircraft in the sky is becoming was pointed out recently in a study made by scientists at the University of Michigan's Institute of Science and Technology. One of the scientists, Dr. Gustave Rabson said: "Today more than 109,000 planes use the same air space and many are flying more than 100 miles per hour. By 1975 we can expect aircraft to more than double their present air mileage .... We must develop a control system to handle incredibly complicated situations rapidly and safely."

Just what does this mean for the future? It means to us that, by 1975, there probably will be over 200,000 aircraft, a goodly percentage flying at more than 1,000 miles per hour. Midair collisions are bound to get worse unless we take heroic electronic measures on the ground and in the air.

As we see it, radar warnings originating in the plane and from the ground can only be a temporary makeshift - they cannot prevail for long. Man's perception and his reactions are hopelessly slow and far too sluggish for the air and space age.

The collision radar in the future must be wholly automatic - it must steer the plane out of its collision course without benefit of pilot. A warning bell or signal will sound, notifying the pilot that the plane is now under radar control. Likewise, large airliners will no longer be "talked down" by the tower during overcasts or at night. The tower operator - not the pilot - will have total electronic control over the plane during its airport approach and its touchdown. The operation will be watched by a bank of special TV cameras near the runway, via closed-circuit automated television receivers in the tower. The rest of the routine landing operation will be by the pilot. - H.G.

*"Needed Electronic Inventions," Radio-Electronics, May 1951.



Posted June 26, 2023

everythingRF RF & Microwave Parts Database (h1)

About RF Cafe

Kirt Blattenberger - RF Cafe Webmaster

1996 - 2024


Kirt Blattenberger,


RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while tying up your telephone line, and a nice lady's voice announced "You've Got Mail" when a new message arrived...

Copyright  1996 - 2026

All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged.

My Hobby Website: AirplanesAndRockets.com | My Daughter's Website: EquineKingdom

Copper Mountain Technologies (VNA) - RF Cafe

Anatech Electronics RF Microwave Filters - RF Cafe