Passenger airlines

FILE - In this Jan. 26, 2003, file photo, a China Airlines Boeing 747-400 sits on the tarmac at the Chiang Kai-shek International airport in Taoyuan, Taiwan. Pilots from Taiwan's China Airlines have gone on strike during the Lunar New Year travel rush Friday, Feb. 8, 2019, in Taiwan, forcing the cancellation of 18 flights over coming days. (AP Photo/Jerome Favre, File)

FILE - In this Wednesday, Jan. 23, 2019 file photo, United Airlines jets are seen as a plane approaches Newark Liberty International Airport, in Newark, N.J. United Airlines will woo high-fare passengers by retrofitting more than 100 planes to add more premium seats on key routes. United announced the moves Wednesday, Feb. 6, 2019. (AP Photo/Julio Cortez, File)

FILE - In this Wednesday, March 26, 2014 file photo, Chief Executive of Ryanair Michael O'Leary speaks during an interview in London. O’Leary will remain for another five years, after the company overhauled its corporate structure and gave its longtime leader a new contract. Europe’s biggest airline by passengers said Monday, Feb. 4, 2019 it will move to a group structure called Ryanair Holdings Plc. (AP Photo/Kirsty Wigglesworth, file)

FILE- In this Jan. 7, 2019, file photo a TSA agent, center, directs passengers through a security checkpoint at New York's John F. Kennedy International Airport. The strain of a 34-day partial government shutdown is weighing on the nation's air-travel system, both the federal workers who make it go and the airlines that depend on them. Unions that represent air traffic controllers, flight attendants and pilots are growing concerned about safety with the shutdown well into its fifth week. (AP Photo/Mark Lennihan, File)

FILE - In this April 29, 2018, file photo, a drone operator helps to retrieve a drone after photographing over Hart Island in New York. Drone sightings reported by airline pilots over New Jersey renew questions about how to accommodate the popular devices into the nation’s airspace. The ability of drones to interfere with aviation is likely to get worse as the number of machines multiplies. Many store-bought drones come with technology to prevent owners from flying them near airports, but there are hacks, and home-built machines don’t necessarily include those protections. (AP Photo/Seth Wenig, File)

Security lines at Hartsfield-Jackson International Airport in Atlanta stretch more than an hour long amid the partial federal shutdown, causing some travelers to miss flights, Monday morning, Jan. 14, 2019. The long lines signaled staffing shortages at security checkpoints, as TSA officers have been working without pay since the federal shutdown began Dec. 22. (John Spink/Atlanta Journal-Constitution via AP)