Boeing's new 777X widebody offers a suite of cabin comforts, like dimmable windows, sunset mood lighting, and a system to minimize turbulence.Pete Syme/Business InsiderAfter years of delays, Boeing's upcoming 777X began certification flight testing in mid-July.The design boasts a suite of cabin comforts, like bigger windows and reduced feelings of turbulence.Airlines can customize the mood lighting with specific colors and scenes, like the northern lights.Boeing may be entangled in its 737 Max fiasco, but it's earning some wins with its upcoming new flagship widebody, the 777X.The aircraft, which is based on the classic 777 and will come in two passenger variants started certification flight testing in mid-July.It is the next step in clearing Boeing's new plane for passenger flights after nearly five years of delays and more than $1 billion in abnormal expenses."The certification flight testing will continue validating the airplane's safety, reliability, and performance," a Boeing spokesperson told Business Insider.