National air transport system

This entry includes four subfields describing the air transport system of a given country in terms of both structure and performance. The first subfield, number of registered air carriers, indicates the total number of air carriers registered with the country’s national aviation authority and issued an air operator certificate as required by the Convention on International Civil Aviation. The second subfield, inventory of registered aircraft operated by air carriers, lists the total number of aircraft operated by all registered air carriers in the country. The last two subfields measure the performance of the air transport system in terms of both passengers and freight. The subfield, annual passenger traffic on registered air carriers, includes the total number of passengers carried by air carriers registered in the country, including both domestic and international passengers, in a given year. The last subfield, annual freight traffic on registered air carriers, includes the volume of freight, express, and diplomatic bags carried by registered air carriers and measured in metric tons times kilometers traveled. Freight ton-kilometers equal the sum of the products obtained by multiplying the number of tons of freight, express, and diplomatic bags carried on each flight stage by the stage distance (operation of an aircraft from takeoff to its next landing). For statistical purposes, freight includes express and diplomatic bags but not passenger baggage.