Boeing 777X

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The Boeing 777X is a new series of the long-range wide-body twin-engine Boeing 777 family that is under development by Boeing Commercial Airplanes. The 777X is to feature GE9X new engines, new composite wings with folding wingtips, greater seating in the cabin, and technologies from the Boeing 787. The 777X series was launched in November 2013 with two variants: the 777-8 and the 777-9. The 777-8 has seating for 365 and range of 8,690 nmi (16,090 km) and the 777-9 has seating for 414 and range of over 7,525 nmi (13,940 km). The -9 is to fly in the first quarter of 2019 with deliveries to begin in December 2019.

The internal cabin width is increased from the previous 777 models' 231 to 235 in (587 to 597 cm) through thinner interior cabin walls and better insulation to allow 18.0 in (46 cm) wide seats in 10-abreast economy. The 777X will feature cabin design details requiring structural changes that were originally introduced on the Boeing 787 Dreamliner: larger windows, higher ceilings, more humidity and lowered cabin altitude to 6,000 ft (1,800 m). Its flight deck is similar to the 787 cockpit with large displays and head-up displays, plus touchscreens replacing cursor control devices and folding wingtips controls.

For the 400+ seats 777-9, new engines should improve fuel consumption by 10%, with the longer, carbon-fiber wings adding a projected 7% improvement. As 4 to 5% of fuel savings is lost from the 12 tons heavier basic structure of the larger airliner, the net fuel efficiency gain is projected to be 12 to 13%. Ten-abreast seating instead of nine with a longer fuselage enable a fuel burn per seat reduction of 20% compared to the 365 seat 777-300ER. The longer-range 355 seats 777-8 should have a 13% improvement in fuel consumption with 10 fewer seats than the 300ER.

To stay within the size category of the current 777 with a less than 213 ft (65 m) wingspan, it will feature 11 feet (3.5 m) folding wingtips supplied by Liebherr Aerospace. The mechanism was demonstrated for Aviation Week at the Boeing Everett Factory in October 2016: the folding movement should be complete in 20 seconds and be locked in place at the end. Specific alerts and procedures are needed to handle a malfunction.

Its maximum takeoff weight is targeted for 775,000 lb (351.5 t) like the 777-300ER but Boeing hopes to have at least a 10,000 lb (4.5 t) margin at introduction. Boeing claims the -8 will be 4% more fuel efficient and cost effective than the A350-1000, while the -9 would be 12% more fuel efficient and 11% more cost effective.[45] Lufthansa, when it ordered both, stated the A350-900 and the Boeing 777-9X will consume an average of 2.9 L/100 km per passenger.

As existing regulations do not cover the folding wingtips, the FAA will issue special conditions, including proving their load-carrying limits, demonstrating their handling qualities in a crosswind when raised, alerting the crew when they are not correctly positioned while the mechanism and controls will be further inspected. Those ten special conditions were to be published on May 18, 2018, covering worst-case scenarios.

Next step: The Folding Passengers

 

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