Which are the major regions of the world having a dense network of airways?

Explanation

Frequent air services are available to many parts of the world. Although, U.K. pioneered the use of commercial jet transport, U.S.A. developed largely postWar international civil aviation. Today, more than 250 commercial airlines offer regular services to different parts of the world. Recent developments can change the future course of air transport. Supersonic aircraft, cover the distance between London and New York within three and a half hours. 519 located In the Northern Hemisphere, there is a distinct east-west belt of inter-continental air routes. Dense network exists in Eastern U.S.A., Western Europe and Southeast balle Asia. U.S.A. alone accounts for 60 per cent of the airways of the world. New York, London, Paris, Amsterdam, Frankfurt, Rome, Moscow, Karachi, New Delhi, 9159 Mumbai, Bangkok, Singapore, Tokyo, San Francisco, Los Angeles and Chicago bare the nodal points where air routes converge or radiate to all continents.