This third edition of Straight and Level thoroughly updates the previous edition with extensive comments on recent industry developments and emerging business models. The discussion is illustrated by current examples drawn from all sectors of the industry and every region of the world. The fundamental structure of earlier editions, now widely used as a framework for air transport management courses, nonetheless remains unchanged. Part 1 of the book provides a strategic context within which to consider the industry's economics. Part 2 is built around a simple yet powerful model that relates operating revenue to operating cost; it examines the most important elements in demand and traffic, price and yield, output and unit cost. Part 3 probes more deeply into three critical aspects of capacity management: network management; fleet management; and revenue management. Part 4 concludes the book by exploring relationships between unit revenue, unit cost, yield, and load factor. Straight and Level has been written primarily for masters-level students on aviation management courses. The book should also be useful to final year undergraduates wanting to prepare for more advanced study. Amongst practitioners, it will appeal to established managers moving from functional posts into general management. More broadly, anyone with knowledge of the airline industry who wants to gain a deeper understanding of its economics at a practical level and an insight into the reasons for its financial volatility should find the book of interest.