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NOW THEREFORE : The Assembly endorses the action taken by the Interim Council in creating the Special Radio Technical Division to consider, among other matters, the problems of co-ordination among member States of technical research and development, which may lead to improvements in air navigation radio facilities and related Standards, Practices .and Procedures. XXVII UNIFICATION OF NUMBERING AND SYSTEMS OF DIMENSIONING IN CONNECTION WITH INTERNATIONAL CIVIL AVIATION Whereas : The wording of the fourth resolution of the Final Act of Chicago is as follows : " Whereas : a standard system of measurements in all rules and regulations pertaining to air traffic on international and intercontinental airways would greatly contribute to the safety of these operations ; and " Whereas : it is considered of high importance that figures used in rules and regulations and other data, with which aircrews and other operational personnel have to deal in the preparation of and during flights over various countries, should consist of round figures which can easily be remembered ; " The International Civil Aviation Conference Resolves : 1. That in those cases in which it appears impracticable or undesirable to make use of the metric system as a primary international standard, units in publications and codes of practice directly affecting international air navigation should be expressed both in metric and English systems ; and "2. That the Provisional International Civil Aviation Organization shall make further unification of numbering and systems of dimensioning and specification of dimensions used in connection with international air navigation the subject of continuing study and recommendation." Whereas : The Universal adoption of a, standard method of measurements in civil avaiation is generally recognized to be desirable, notably for the safety of air navigation ; and Whereas : It is particularly necessary for the safety of air navigation to achieve at the earliest possible date a uniform practice in the units of measurements used between aircraft in flight and ground stations in the exchange of air traffic control instructions and information required for the safe operation of aircraft; and Whereas : ICAN adopted the metric system as a standard for air navigation and a number of ■States have adopted the metric system, some of them many years ago, as a national standard and such States would be reluctant to reverse their policy; and Whereas : The dimensional units used in the PIC AO " Recommendations for Standards, Practices and Procedures " and those adopted by the Council following the recommendations of the Dublin Conference and those recommended by the Paris Air Navigation Meeting are not in all respects the same; and Whereas : The majority of flying and air traffic control personnel in the world now use methods ■of measurement other than the metric system, the majority of aircraft instruments used are calibrated in units that are non-metric, the majority of maps used in flight are on a non-metric basis and the immediate substitution of the metre for the foot as a unit of vertical measurement presents an element of hazard ; and W t hereas : The Council has created a Special Committee to report on the standardization of -dimensional systems in international air navigation;

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