However, faced with increased competition and rising fuel costs, airlines have already achieved considerable productivity gains. Today, very few seats are “wasted”, with historically high load factors across most major markets and flows.

So, with traffic levels easily surpassing pre-September 2001 levels and with demand continuing to increase, there is now little flexibility in a system working at near maximum capacity. In fact, the gradual rise in congestion has also returned to pre-2001 levels and is a problem already being faced by many of the world’s most important airports and cities. Therefore, any future growth of traffic and frequencies will be an increasing challenge to airport infrastructure and air traffic management. That increasing congestion, coupled with the eventual diminishing returns from increased frequencies and the overall growth of the world fleet, has seen the emergence of a clear trend towards larger aircraft. This is evident in all seat categories, from smaller regional aircraft to very large aircraft, and will result in the average aircraft size increasing by as much as 25% over the next 20 years.

This GMF assumes that all necessary infrastructure improvements, including those already planned, will be undertaken during the forecast period. However, given the substantial investments and time required to carry out such developments, there is the possibility that not all the changes necessary may be achieved. In which case, average aircraft size could increase even more than anticipated levels and airlines could, therefore, be forced to acquire more, larger aircraft, across the whole spectrum of those available, to meet demand.