The Boeing 787 Dreamliner and Airbus A380 are the aircraft most frequent flyers seek out to take to the skies in comfort. But another significant new model is set to be thrown into the mix, as Boeing has announced progress on its 777X jetliner, which it says will be "the largest and most efficient twin-engine jet in the world". Both Emirates and Etihad Airways have placed orders for the aircraft, along with All Nippon Airways, Cathay Pacific, Lufthansa and Singapore Airlines. Boeing has revealed that its fully assembled static test airplane has been completed at its facility in Everett, Washington. It will now begin a year of testing to verify its design strength and safety, Boeing said. This test plane will not enter commercial service or take to the skies, but it shows that Boeing is moving closer to bringing the 777X into service, with deliveries to customers predicted to be in 2020. As well as larger windows, a wider cabin and new lighting – all inspired by the 787 Dreamliner – the 777X features the first foldable wing-tips, which enable an extended span of 7 metres and maximises fuel efficiency. The design of the wing tips won approval from the US regulator Federal Aviation Administration in May and allows the bigger wings to fit into the standard airport parking spaces. Instead of aluminium, Boeing has made the new wings out of carbon-fibre composites and once the aircraft touches down, the tips start to rotate until they point up towards the sky. The 777X model includes the 777-8 and 777-9. The former will seat between 350 and 375 passengers, while the latter can carry 400 to 425 passengers, both in a two-class configuration. The 777-8 has a range of 16,110km – far enough for it to create <a href="https://www.thenational.ae/lifestyle/travel/world-s-second-longest-flight-touches-down-in-london-from-perth-1.715878">a new world's longest flight</a> – and the 777-9 can travel 14,075km. Boeing says the 777X will have 12 per cent lower fuel consumption and 10 per cent lower operating costs than its competition. ____________ <strong>Read more:</strong> <strong><a href="https://www.thenational.ae/lifestyle/travel/a-guide-to-picking-the-perfect-seat-for-your-flight-1.769592">A guide to picking the perfect seat for your flight</a> </strong> <strong><a href="https://www.thenational.ae/business/aviation/airbus-ageing-a380-gets-glimmer-of-new-life-1.751908">Airbus' ageing A380 gets glimmer of new life</a></strong> <strong><a href="https://www.thenational.ae/business/aviation/airbus-asks-top-execs-to-delay-retirement-amid-engine-woes-1.751998">Airbus asks top execs to delay retirement amid engine woes</a></strong>