7E7

7E7 is Boeing's internal program designation for a family of mid-size, long-range airliners that ultimately entered commercial service as the Boeing 787 Dreamliner. Announced in the early 2000s, the 7E7 project was conceived to deliver substantially improved efficiency and environmental performance through advances in materials, aerodynamics, and propulsion.

Design and technology aspects associated with the 7E7 program emphasized a lightweight airframe constructed with a high proportion of composite materials, notably for the fuselage and wings. The aircraft was planned to employ an all-new electrical architecture and more efficient, modern engines to reduce fuel burn and maintenance costs. The cabin was targeted for a larger, more comfortable experience, including higher humidity and larger windows, together with other efficiency-focused innovations.

Variants in the planned family were expected to accommodate a range of capacities, roughly in the 210 to 290 passenger class, with extended range options for long-haul service. The program sought to redefine operating economics for long-range flights and to enable new route structures for airlines.

Development of the 7E7 faced significant challenges, including delays and cost overruns, and the project underwent restructuring as it transitioned to production. The first flight of the aircraft occurred in December 2009, and commercial deliveries began in 2011 under the 787 Dreamliner branding. The internal 7E7 designation was gradually superseded as the program became known publicly as the 787, shaping the next generation of widebody design and influencing subsequent aircraft programs with its emphasis on composite construction and all-new systems architecture.