Recent advances in technology and miniaturization have seen the development and deployment of electronic flight bags (EFBs), which contain electronic manuals and documents, as well as automated calculation and navigation tools. According to United Airlines, a conventional paper-based flight bag contains an average of 12,000 sheets of paper per pilot. The airline estimated that deployment of an EFB system running on Apple iPads would save the airline nearly 16 million sheets of paper a year, as well as saving 1,230,000 litres (326,000 US gal) of jet fuel due to the reduced weight on board the aircraft.[1]