Papers relating to the foreign relations of the United States, 1930, Volume I

811.7442/44

Minutes of Informal Canadian–United States Conference on Aviation Radio Held at U. S. Customs House, New York City, April 10–11, 1930

New York, April 10–11, 1930

First Meeting

The meeting opened at 10:45 A.M.

The following persons were present:

Representing Canada:

• Commander C. P. Edwards, Director of Radio Telegraph Branch, Department of Marine,
• Mr. G. C. W. Browne, Chief Inspector, Radio Telegraph Branch, Department of Marine,
• Major W. A. Steel, Royal Canadian Signals, Department of National Defense,
• Captain W. L. Laurie, Royal Canadian Signals, Department of National Defense.

Representing the United States:

• Commissioner W. D. L. Starbuck, Federal Radio Commission,
• Colonel Clarence M. Young, Assistant Secretary of Commerce,
• Mr. W. R. Vallance, Assistant Solicitor, State Department,
• Captain F. C. Hingsburg, Chief Engineer, Airways Division, Department of Commerce,
• Dr. C. B. Jolliffe, Chief Engineer, Federal Radio Commission,
• Mr. Gerald C. Gross, Engineer, Federal Radio Commission.

Commissioner Starbuck presided over the meeting as chairman of the host delegation. He welcomed the representatives present and called attention to the fact that it seemed to be the unanimous desire to make this conference a purely informative one for the mutual exchange of ideas between the representatives of aviation radio from both countries present.

He then suggested that Colonel Young, Assistant Secretary of Commerce for Aeronautics, describe the purpose of the conference.

Colonel Young pointed out that the interests of the United States and Canada in aviation radio are of the same character, and stated that aviation radio falls naturally into two distinct classifications:—1. Radio navigation aids to aircraft; 2. Radio communication with aircraft.

Commander Edwards then stated that all aviation services in Canada, both civil and military, come under the Department of National Defense, while the allocation of frequencies comes under the jurisdiction of the Department of Marine. Representatives of both Departments were included in the Canadian group present. He suggested that the logical procedure for the conference might be to have the system now being followed in the United States outlined, following which the Canadian representatives could describe the procedure now being followed in Canada, and after this mutual exchange of information some satisfactory arrangement might be worked out.

At the suggestion of the Chairman, Captain Hingsburg then proceeded to describe the present system of radio aids to air navigation being followed in the United States.

Starting with the teletype circuits which are being extended over United States Civil Airways, he described the operation of these circuits and stated that data are being collected and brought up to the minute every fifteen minutes so that a pilot can depend upon regular weather broadcasts at regular periods. In addition to the collection and dissemination of weather information, the same teletype circuits are used for message and other dispatch work.

The information collected by the teletype circuits is broadcast on standardized 2 K W transmitting sets operating in the frequency band 237–350 kc.

Transmitting sets used for radio beacon work operating most of the time are only interrupted for the periodic weather broadcasts. These broadcasts last usually only three minutes so that the interruption to the beacon service will not be long.

The present beacon system makes use of the aural signal, but in view of the development of the visual beacon it is planned to install a double beacon at one of the stations along the airways, namely Bellefonte, Pennsylvania, so that practical tests on both systems may be carried on. There are at present nine aural beacons in operation and it is planned by next summer to have thirty-five beacons of the aural type operating.

Commander Edwards then pointed out that the International Radio Convention^40a applies only to international service, and that the convention provides that for regional groups special arrangements may be made. For example, on the North American continent if new arrangements appear to be desirable between the United States, Canada, Mexico and other nations, such arrangements may well be made by a Regional Agreement. Commander Edwards then asked concerning the tie-up between marine and aviation beacons.

Captain Hingsburg replied that in this country the services were handled in the same department and were so arranged as to avoid interference. In all cases where interference had been found it has been adjusted by the proper distance separation. He further stated that some thought had been given to the question of having one additional frequency in the same general band for communication messages to planes which messages might be too long to interrupt the regular beacon service. At Commander Edwards’ inquiry Captain Hingsburg explained that the band referred to was from 237 to 350 kilocycles.

Major Steel then asked as to how planes would be taken care of from stations using both the visual and aural systems, and Captain Hingsburg replied that only one station at present was proposed for such joint testing and that both services would be made available.

Commissioner Starbuck then suggested that the only object of the conference is to provide safe and reliable communication for aircraft in flight and said that undoubtedly the conference will find itself in general agreement. He then asked Mr. Gross to describe the radio communication system now being followed in the United States.

Mr. Gross then described in detail the aviation plan adopted by the Federal Radio Commission in cooperation with other United States governmental departments and commercial aviation companies. The plan was distributed to the representatives present and appears as Annex A⁴¹ to these minutes. He pointed out that the plan was intended to be flexible and had been modified from time to time to suit the requirements of the growing art. There are undoubtedly a number of ways in which the aviation plan can be improved and it is proposed to improve and revise it gradually as more and more practical operating data become available. After some general discussion on this aviation plan, the conference adjourned for lunch at 1 p.m.

The meeting reconvened after lunch. Major Steel then described the Canadian system of aviation radio, pointing out that most of the airplane companies are subsidized by air mail contracts. The air mail route starts from Halifax and runs through to Windsor. At Windsor the mail is at present transferred through St. Paul and Minneapolis by American companies to Winnipeg. From Winnipeg the mail is carried by Canadian companies to Vancouver.

It is proposed that planes may leave Montreal and proceed through Ottawa to Sudbury. From Sudbury they would travel along the north shore of Lake Superior to Winnipeg. The other main route is the one flying into northern Canada from Edmonton as shown on the attached map^41a from opposite page 40 of the 1928 Canadian Aviation Report. In general the radio service is conducted in Canada on 1200 meters (250 kc). The information is collected by teletype and broadcast by radio.

In general the system is similar in nature to that used in the United States with the difference that one transmitter is used jointly for aural beacon service, visual beacon service or voice.

Three stations are now operating on the above system, in Montreal, Toronto and Winnipeg. It is planned to put eight more into service by next summer.

After some discussion on the merits of the visual vs. the aural beacon, Major Steel stated that the Canadian authorities are strongly in favor of the visual beacon and intend using that system.

Commander Edwards suggested that a technical committee be appointed to consider the question of how best to link the systems operated by both countries.

During some discussion on receiving sets Major Steel pointed out that a number of receivers today will cover the range from 850 to 1300 meters (353 to 230 kc), and Captain Hingsburg stated that the best ratio on frequency range is 2.5 or 2.0 to 1. Major Steel then stated that the Canadian authorities do not propose to have communication traffic carried on within bands used for beacon and weather service. It is expected, however, to handle emergency messages of an urgent nature for operating companies by broadcasts to the planes.

Major Steel further stated that it is proposed to carry on communication services in entirely different bands but that 100 meters (3000 kc) is entirely too long a wave for this work in Canada.

Commander Edwards then stated that the communication might perhaps be in the band around 5000 kc. Itinerant plane communication service is especially important in Canada, but due to the more northerly latitudes higher frequencies are necessary.

Major Steel then suggested that the harmonic relationship might be followed and that if the United States used around 3000 kc, Canada might use a frequency in the neighborhood of 6000 kc. He also stated that the Canadian government contemplated a series of stations from Halifax to Vancouver to be assigned one frequency throughout the chain. Commander Edwards then stated that with reference to his previous suggestion it might be desirable to appoint a technical committee to study this question and formulate some general statements of policy, such committee to report to the main conference at 2 P.M., Friday, April 11.

Without objection the suggestion was carried and the following committee was designated for this work:

• Major Steel
• Captain Laurie
• Mr. Browne
• Captain Hingsburg
• Dr. Jolliffe
• Mr. Gross

The Committee arranged to meet at 8:30 P.M. Thursday, April 10, and the following morning if necessary.

The conference then adjourned at 5:45 P.M.

Second Meeting

The second and last meeting of the Conference opened at 2 P.M. April 11, 1930.

The following persons were present:

Representing Canada:

• Commander C. P. Edwards, Director of Radio Telegraph Branch, Department of Marine,
• Mr. G. C. W. Browne, Chief Inspector, Radio Telegraph Branch, Department of Marine,
• Major W. A. Steel, Royal Canadian Signals, Department of National Defense,
• Captain W. L. Laurie, Royal Canadian Signals, Department of National Defense.

Representing the United States:

• Commissioner W. D. L. Starbuck, Federal Radio Commission,
• Captain F. C. Hingsburg, Chief Engineer, Airways Division, Department of Commerce.
• Dr. C. B. Jolliffe, Chief Engineer, Federal Radio Commission,
• Mr. Gerald C. Gross, Engineer, Federal Radio Commission.

Commissioner Starbuck presided. He suggested that the report of the Technical Committee which met Thursday night and Friday morning be read and discussed. Each item of the report was considered separately and discussed at length, and some improvements in the language of the suggested texts were made. The corrected report was adopted unanimously. This appears as Annex 1 to these minutes.

Commander Edwards then brought up the question of priority of marine over aviation beacons in the band 285–350 kc. and considerable discussion took place. After several resolutions touching on the subject had been presented and considered it was decided that no formal resolution should be adopted on this point.

The minutes of the first meeting were then read and after some corrections had been made were adopted.

At 6 P.M. the conference adjourned sine die.

[Annex 1]

Informal Canadian-U. S. Aviation Radio Conference

The coordination of airways communications and radio aids to air navigation in Canada and the United States is desirable, and the following principles are proposed as a guide in the operation of these systems.

The conference recommends that the two Governments study these principles and attempt to apply them to their respective systems and that by correspondence and future conferences these principles be further developed and closer coordination obtained.

It is further recommended that:

1. The International Air Calling Frequency 333 kc. be not required regionally for aircraft or aeronautical stations in Canada or the United States.

2. It be recognized that a frequency separation of 6 kc. is ordinarily sufficient between stations operating radio range beacon and radio telephone services.

3. A minimum distance of 750 miles between radio beacon stations operating on the same frequency is desirable. It is recommended that this separation be maintained between nations, although in some cases it may be necessary to reduce the separation within the interior of either country.

4. The following frequencies:

• 237
• 240
• 248
• 278 kc.

out of the band 194–284 kc. be reserved regionally for air services.

5. The following frequencies shall remain free from assignments in the United States within 750 miles of Canadian airways radio stations:

• 248
• 290
• 296
• 326
• 332 kc.

In addition, no further assignments in the United States should be made on the following frequencies within 750 miles of Canadian airways radio stations:

• 240
• 314 kc.

6. The following frequencies shall remain free from assignments in Canada within 750 miles of United States airways radio stations:

• 254
• 260
• 266
• 272
• 284
• 302
• 308
• 320
• 338
• 344
• 350

7. The frequency 278 kc. should be reserved primarily for low power airport use.

8. One frequency, approximately 237 kc. shall be reserved for emergency messages from ground stations to aircraft in cases where such messages might interfere with the regular airways beacon service.

9. The following frequencies should be reserved for Canadian stations operating along the Canadian Transcontinental Airways from Halifax to Vancouver:

• 3492
• 5630 kc

The United States authorities will discuss with aviation companies operating between Chicago, Minneapolis, and St. Paul a change of frequencies from those now specified in the U. S. Aviation Plan for the Green Chain to the Red Chain frequencies in order that Canadian planes flying from Winnipeg to Minneapolis and St. Paul will be able to have closer frequency coordination.

10. The United States will continue to use 3106 kc. as a national calling frequency and Canada will use the frequency 5630 kc. for the same purpose, since the experience gained to date in the United States and Canada would indicate that the common calling frequency selected in the United States might not be equally suitable in Canada.

1. Signed at Washington, November 25, 1927, Foreign Relations, 1927, vol. i, p. 288.
41. Not printed.
42. Not reproduced.