Aerospace engineers occasionally come up with solutions to seemingly insurmountable challenges. This year's 40th anniversaries of the Moon landing and the maiden flight of Concorde leap to mind. But even the most enthusiastic industry proponents accept that history is littered with abortive attempts to bring disruptive technologies into the mainstream.

Commercial aviation is approaching a crossroads at which it must decide whether to adopt radical propulsion concepts that require a rethink of fundamental aspects of its operations. The proposed use of open rotor powerplants on the next generation of 150-seat airliner families makes for great marketing publicity and is effective in attracting research euros from governments, but industry needs to take a realistic view of the obstacles that lie ahead.

Problems have beset "conventional" airframe projects such as the A380 and 787, so do Airbus and Boeing have the appetite to risk radically overhauling their designs to accommodate open rotor? Certification rules must also be revised, and noise issues overcome by adopting techniques such as steep approach.

Most importantly, the potential benefits of air traffic management efficiency gains must not be forgotten. ATM advances coupled with advanced high-bypass turbofans still represent industry's most realistic route to a step-change reduction in fuel consumption.

Source: Flight International