On the eve of the Farnborough Air Show, Boeing has put out its traditional long-term outlook for the commercial aircraft market. Given all the problems facing the industry – high oil prices, the credit squeeze, the weakening of economic activity, slowing airline traffic growth in some markets – the US manufacturer has inevitably scaled down its forecast on the size of the world aircraft fleet in 20 years’ time.

It is expecting that 35,800 airliners will be in operation at the end of 2027 instead of the 36,400 it was forecasting before the subprime crisis and its related effects started taking their toll on world economic sentiment. That is a shortfall of only 600 airliners and under the circumstances the latest Boeing outlook looks extremely optimistic. But then airliner manufacturers – be it Boeing or its European rival Airbus – have always sought to take refuge in what they argue are the encouraging long-term fundamentals of the air travel industry, especially when the sector is facing one of its cyclical downturns.