The U.S. Air Force operates the "world's largest airline" and every $10-per-barrel increase in crude oil boosts its annual operating costs by $610 million, Air Force Secretary Michael Wynne said. The Air Force's bill for aviation fuel was about $6 billion in fiscal 2007, Wynne told a defense industry group. He declined to predict what the total would be for 2008. REad full via: enn.com