Boeing has completed the first 787-9 Dreamliner.

The second member of the super-efficient 787 family rolled out of the Everett, Washington, factory today to the flight line, where teams are preparing it to fly later this summer.

At 20 feet longer than the 787-8, the 787-9 will extend the 787 family in both capacity and range, carrying 40 more passengers an additional 300 nautical miles.

The 787-9 leverages the visionary design of the 787-8 such as its exceptional environmental performance — 20 per cent less fuel use and 20 per cent fewer emissions than similarly sized airplanes — and passenger-pleasing features.

With the second and third airplanes in final assembly, Boeing and the 787-9 are on track.

First delivery to launch customer Air New Zealand is set for mid-2014.