Infrastructure to allow in-flight refuelling of medium-haul airliners should be put in place if governments are serious about reducing aircraft emissions, a new report says.

A study into mitigating the environmental impact of aviation by the Greener by Design science and technology sub-group of the UK Royal Aeronautical Society details a series of research priorities for propulsion and airframe manufacturers and suggests interim changes to aircraft operation including routeing air traffic to avoid cold wet air, formation flying and air-to-air refuelling for long-haul flights.

John Green, chairman of the sub-group, says it will take a change in mindset for airlines and governments to accept such radical proposals, but that they should be taken seriously. “Formation flying could save around 10% in fuel burn by NASA estimates, but flying close together goes against the current ATM [air traffic management] grain that keeps aircraft apart in the skies,” he says.

Similarly, although medium-haul twin-engined aircraft are more fuel efficient than long-range variants, airlines reject them on commercial grounds because they require multiple stopovers. Green believes operators could be persuaded to re-examine their options if air-to-air refuelling were viable. “If you moved to a global fleet of aircraft with ranges of around 5,000km [2,700nm], with refuelling bases ideally situated in the middle of nowhere near oil refineries, you could design aircraft to take off almost empty,” he says.

Arguments that in-flight refuelling is not safe are undermined by its current use for head-of-state transport, not least by the USA. “If it’s good enough for Air Force One, then it must be good enough for ordinary passengers,” says Green.


Source: Flight International