A developmental 777X flight deck. The five large-format display screens will mean the flight deck will look like a 787's, although Boeing says similar flight control laws, Rockwell Collins avionics and positioning control switches in the same places as current-generation aircraft will maximise commonality.
Touchscreen flight deck displays will feature resistive technology that, by requiring a firm rather than a light touch to operate the display, is designed to avoid unintentional interaction.
High-speed wind tunnel testing for the 777X was carried out in the Boeing Transonic Wind Tunnel in Seattle. Data from the high-speed tests helped with configuration development by validating computational fluid dynamics predictions and support preliminary loads cycle development.
The 777-9 will be the largest twin-jet airliner ever built and it will be 10ft (3m) longer than the 777-300ER; four extra fuselage frames give it the extra length compared to the current-production model.
At 105ft (32m) long, the spar is the largest single-piece composite part ever developed for an airliner.
The Boeing 777-9X and 777-8X (at rear) were officially launched on November 17, 2013 with commitments from four airlines.
The 777-9 is optimised for around 400 seats and 8,200nm (15,185km) range, and the 777-8 for approximately 350 seats and 9,300nm (17,220km) range.
The two Boeing 777X versions have attracted more than 300 orders so far, with Singapore Airlines recently firming an order for 20 777-9s.
A folding wingtip mechanism will extend the 777Xs' wings to their full 235ft 5in (71.7m) span for flight, the mechanism folding upwards to narrow the aircraft's wings for ground operations and ensure taxiway and gate compatibility.
With an 8,131ft3 (230.2m3) lower-deck cargo hold, compared to 7,120ft3 (201.6m3) on the 777-300ER, the 777-9 will be able to carry 48 LD-3s (26 in the forward hold and 22 in the rear hold).
The Boeing 777X will feature raked, folding wingtips.