The Fantastic FIVE

Engineers at NASA Langley, NASA Glenn, and The Boeing Co. investigate new aircraft concepts designed to improve fuel economy.

The commercial airplane designer is faced with the challenge of balancing many factors to achieve an optimal design, namely, how to reduce jet fuel use while also maintaining or improving emissions, noise, performance, operating costs, range, maintainability, and payload capabilities. Often, fuel efficiency improvements run counter to other design constraints imposed on the aircraft manufacturer by market forces. However, emerging engine and airframe technologies will help to continue the historical trend toward reduced fuel use. NASA and The Boeing Co. have begun evaluating future aircraft concepts designed for reduced fuel use and emissions. Both organizations are studying concepts that could become feasible around the year 2015, given a sufficient development effort.

Fuel use makes up about 20% of the cash operating cost of a medium commercial airplane (Figure 1). In the quest to improve operating costs, engine and airframe technology advancements have made current turbofan-powered aircraft approximately 70% more fuel-efficient than 1960s-era jet aircraft (Figure 2). However, there has been some leveling off of efficiency gains in the last 15 years because of diminishing returns on technology improvements.