Solving the jet-engine jigsaw

In a few weeks a large chunk of the global aerospace community will gather for the

, an event that unquestionably ranks among the great engineering showcases of the world.

Four years ago, the Airbus A380 made its maiden public flight above the Le Bourget runway to gasps of wonder at the sheer scale of the latest addition to the skies.

The history of aero-engineering is one of challenges faced and overcome, boundaries reached and surpassed. Flying higher and faster in larger, safer planes capable of ever longer ranges has dominated the industry's agenda for most of its century or so of existence. The challenges facing the sector, and particularly commercial aviation, as it enters its second 100 years are clear to see in this issue of

, the latest in our occasional series of special themed editions looking at the future of aerospace technology.

You can add cleaner and quieter to the list. Two of the biggest names in the industry, Prof Ric Parker, head of research and technology at

, and Axel Krein, his equivalent at

, will between them shape the engines and the aircraft that will in years to come delight the crowds at Paris, Farnborough and beyond.

It is an understatement to say that these two have got a lot on their plates. Not only do they have to push the boundaries of what is technically possible, they have to do it in a way that balances the multitude of often competing demands from those with a stake in the future of commercial aviation (in Rolls-Royce's case, as well as the many other military and civilian markets it serves). The list is a lengthy one: airlines, passengers, airport operators, residents, governments, regulators and environmental campaigners, and many more besides.

Parker's insight into the process of developing cleaner engine technologies is particularly instructive. If anyone doubted the technical challenges involved, an hour spent with Parker would put them straight. This is heavyweight applied science that pushes materials and components to new extremes of performance.

Another theme to emerge is that even as Parker and his engineers work to overcome those challenges, they are not operating in a vacuum. The requirements of customers and — particularly where environmental improvement is concerned — governments and societies will dictate their direction.

Parker points out that two of the leading imperatives placed on future aero engines — that they are more fuel efficient and quieter — could potentially lead technical development along different paths — the quietest engine may not be the most efficient and vice-versa.

It is also interesting to note that even within the aerospace technology community there are differences of opinion over the direction the sector will take. Krein expects biofuels to account for a quarter of the industry's needs by 2025, if a mass-production infrastructure emerges that can support the demand. Parker is less convinced and does not predict a significant role for alternative fuels over the next decade or so.

In aerospace technology as in so many other areas, the wider world cannot expect engineers to produce answers without clear leadership on what, precisely, are the questions.

Let the debate begin.