Homes and business are prime "greening" targets. Even automakers are starting to jump on the bandwagon and are trumpeting their strides. But what about the aerospace industry?

Aviation Week reports on how a newfound eco-consciousness came to the fore at this years Paris Air Show. And while cutting down on pollution is admirable goal shared among all involved, it's the economics behind such efforts that may sway the commercial airline industry.

Even the military is getting into the mix, albeit driven more by fuel-cost concerns than environmental considerations. The U.S. Air Force is building a financial case to convince U.S. airlines to embrace synthetic fuels. It hopes a larger user base would drive down costs. "Every $10 a barrel is essentially $600 million in my annual budget," says USAF Secretary Michael Wynne.

Last year, the Air Force tested and qualified a 50-50 mix of jet and Fischer-Tropsch derived fuels for use on a B-52. Wynne says the next step will be qualifying the synthetic mix on the C-17, which is powered by the Pratt & Whitney F117-PW-100 turbofans.

"The C-17 engine is a direct commercial derivative," Wynne said. "So that will allow our partners in flight--the airline companies if they so choose--to essentially use the data we compile to allow them to fly with synthetic fuels."

The article also goes into some of the engineering and design considerations -- which are, well, considerable -- that must be taken into account to keep future passengers aloft in a more fuel-efficient manner.