British Airways planes taxied at Heathrow Airport on September 9, 2019 in London due to a 48 hour 'walkout', grounding most of its flights over a dispute about the pay structure of it's pilots. GETTY IMAGES
FILE PHOTO: Grounded Boeing 737 MAX aircraft are seen parked in an aerial photo at Boeing Field in Seattle, Washington, U.S. July 1, 2019. Picture taken July 1, 2019. REUTERS/Lindsey Wasson/File Photo