Future subsonic aircraft designs could be powered with turbofan engines that incorporate technology currently under research as part of NASA's ERA project.

Boeing's ERA study design.

Lockheed Martin's study design for NASA's ERA project.

Massachusetts Institute of Technology's double bubble design in the wind tunnel at the NASA Glenn Research Center.

Massachusetts Institute of Technology's (MIT) H-series. The design features a triangular-shaped hybrid wing body aircraft that blends a wider fuselage with the wings for improved aerodyamics. The large centre body creates a forward lift that eliminates the need for a tail to balance the aircraft.

MIT's double bubble series design concept is based on a modified tube-and-wing structure that has a very wide fuselage to provide extra lift.