Boeing successfully completed the first test flight of its much-anticipated 777X widebody jet, marking a rare bright spot for the embattled plane maker following the crisis of its smaller grounded 737 Max model. The US plane maker had originally scheduled the flight for January 23, but was forced to delay it twice due to poor weather conditions at its production facility in Everett, Washington, outside of Seattle. The third attempt to test the world's largest twin-engine jetliner went ahead on Saturday, when the 777X undertook a nearly four hour flight before landing in Boeing Field. “It’s a proud day for us,” Stan Deal, the chief executive of Boeing’s commercial airplane unit, said. “It made all of our employees proud one more time of who we are and what we get to do, by flying a brand new airplane that is going to change the world one more time." The jet will come in two variations – the 777-8 and 777-9. The 777-8 will seat between 350 to 375 passengers, while the bigger variant can carry 400 to 425, both in a two-class configuration. Boeing said it will have 12 per cent lower fuel consumption and 10 per cent lower operating costs than its competition. Its features include folding wing tips, allowing an extended span of seven metres to maximise fuel efficiency, larger windows and "smoother ride technology". The 777X, a larger and more fuel-efficient version of Boeing's successful 777 mini-jumbo, took off outside Seattle at 10.09am local time after high winds forced the company to postpone two earlier attempts this week. Boeing officials said the maiden voyage would last 3-5 hours and herald months of testing and certification before the aircraft enters service with Emirates in 2021, a year later than originally scheduled because of snags during development. The flight is a boost for Boeing as it grapples with the grounding of its 737 MAX, following two fatal crashes that killed 346 people. "To me this is the flagship for the big airlines around the world ... it represents the great things we can do as a company," 777X marketing director Wendy Sowers told reporters when asked about the flight's importance in light of the MAX crisis. Boeing says it has sold 309 of the aircraft – worth more than $442 million each at list prices. The 777X will compete with the recently introduced Airbus A350-1000 which seats about 360 passengers. Both reflect the growing range and efficiency of twin-engined jets that are steadily displacing their older four-engined counterparts. The 777X behemoth was launched at the Dubai Airshow in 2013 amid much fanfare when Emirates placed a record-breaking order. Since then, orders for the jet have slowed down. Boeing's sales chief Ihsanne Mounir <a href="https://www.thenational.ae/business/aviation/boeing-expects-777x-orders-and-hopes-for-trade-war-respite-1.920887">expects a rise in orders </a>of the re-engined 777X within three years when airlines start replacing ageing fleets of the older previous 777-300ER models, he told reporters in October in Seattle. However, there's concern about wide-body jet demand due to overcapacity and economic weakness in the market. “It is feeling like the plane is too big for most markets, for most airlines,” George Ferguson, an aviation analyst with Bloomberg Intelligence, said. The aircraft is expected to face more scrutiny from US and global aviation regulators in the light of Boeing's 737 Max crisis that shook confidence in the Chicago-based jet maker. The troubled plane is not expected to gain regulatory approval to fly before mid-2020. The Federal Aviation Administration (FAA) vowed to ensure a rigorous scrutiny of the 777X is conducted, while launch customer Dubai-based Emirates wants to see upto 16 months of testing to ensure it is safe and meets performance expectations.