Worldwide, air transport has proven very resilient over the past 45 years, despite periodic major crises. This was highlighted by Airbus COO customers John Leahy to international aerospace journalists in Hamburg on Tuesday.

Since 1970, when the Boeing 747 Jumbo jet first entered commercial service, air traffic has grown by 12 times, he pointed out. Crises, namely, the oil crises of the early 1970s and 1980s, the Gulf crisis of 1990/1, the Asian crisis of the later 1990s, the crisis triggered by the terrorist attacks of September 11, 2001 ("9/11") on the US, the Severe Acute Respiratory Syndrome (better known as SARS) outbreak of the early 2000s and the 2008 financial crisis, only inflicted temporary delays in the growth of the sector. "Now, we are double the size of the industry on 9/11," he noted.

This growth is forecast to continue. Air traffic (measured in revenue passenger kilometres or RPKs) is predicted to double again over the next 15 years. In geographic terms, this growth is being driven by emerging market countries. Even though the rate of growth in emerging markets is slowing, it is "still enormous. That's what's driving this industry."

Socioeconomically, the key factor is the rise of the middle class. "What does it mean if you are middle class? You have disposable income," pointed out Leahy. Also, a bigger middle class also means more business travel.

The Asia-Pacific region will see the greatest growth; from 1 223-million middle class people in 2014, the region should see this number grow to 2 579-million by 2034. The other emerging market countries are predicted to see their combined middle class populations increase from 778-million to 1 398-million. The sizes of the middle classes in Europe and North America will also increase, but, as these are mature societies, only slightly. In 2014, the middle class accounted for 37% of the global population; in 2024 it will be 46% and by 2034 it will reach 55%.

As a result, Asian Pacific airlines will see their share of global air traffic, in RPKs, increase from 29% in 2014 to 36% in 2034. Europe's share, 25% in 2014, will be 21% (although Europe will retain its number two position in its share of air traffic worldwide). North America will go from a 25% share to a 17% share (and so from second equal place to third place). The Middle East will rise from 9% to 13%, Latin America from 5% to 6%, while the airlines of States which emerged from the former Soviet Union and African airlines will retain their current shares of global air traffic, at 4% and 3% respectively - but the amount of air traffic will be significantly larger in 2034. "The growth of the middle class will make the Asia Pacific the main centre of air travel around the world," stated Leahy.

*Keith Campbell is attending the Airbus Innovation Days 2016 as a guest of the company.