Passenger airlines

Stranded passengers set to travel with Icelandic airline Wow, wait in line at Iceland's international airport in Keflavik, Thursday March 28, 2019. Icelandic budget airline WOW Air ceased operations on Thursday, stranding passengers across two continents. The airline told passengers there would be no further flights and advised them to check flights with other airlines for ways to reach their destinations. (AP Photo/Egill Bjarnason)

FILE - In this Monday, March 18, 2019, file photo, the logo for Southwest Airlines appears above a trading post on the floor of the New York Stock Exchange. The Federal Aviation Administration says a Southwest Airlines Boeing 737 Max jet made a safe emergency landing Tuesday, March 26, 2019, in Orlando, Fla., after experiencing an apparent engine problem. (AP Photo/Richard Drew, File)

FILE- In this March 18, 2019, file photo trader John Santiago works on the floor of the New York Stock Exchange. U.S. stocks edged lower in early trading Monday, March 25, extending losses from a broad sell-off last week, as new economic data stoked investors' worries over slowing global growth. (AP Photo/Richard Drew, File)

FILE - In this Sept. 28, 2015, file photo, workers clean a jetliner at GMF AeroAsia facility at Soekarno-Hatta International Airport in Jakarta, Indonesia. Indonesia's flag carrier is seeking the cancellation of a multibillion-dollar order for 49 Boeing 737 Max 8 jets, citing a loss of confidence in the model following two crashes in the space of a few months. (AP Photo/Dita Alangkara, File)

FILE - In this May 15, 2017 file photo, Frontier Airlines jetliners sit at gates at Denver International Airport. The union representing Frontier Airlines flight attendants says they have reached a tentative contract deal with the Denver-based budget carrier. The Association of Flight Attendants-CWA said both sides agreed to terms for the contract Tuesday, March 19, 2019, but the language still needs to be finalized and approved by the flight attendants' elected union leaders. The union says the deal includes significant pay increases, schedule flexibility, quality of life enhancements and other benefits. (AP Photo/David Zalubowski, File)

FILE - This Friday, June 19, 2015 file photo shows the Department of Transportation Federal Aviation Administration building, in Washington. For more than six decades, the Federal Aviation Administration has relied on employees of airplane manufacturers to do government-required safety inspections as planes are being designed or assembled. But critics say the system, dubbed the "Designee Program," is too cozy as company employees do work for an agency charged with keeping the skies safe while being paid by an industry that the FAA is regulating. (AP Photo/Andrew Harnik, File)

A worker walks up steps to the right of an avionics truck parked next to a Boeing 737 MAX 8 airplane being built for TUI Group at Boeing Co.'s Renton Assembly Plant Wednesday, March 13, 2019, in Renton, Wash. President Donald Trump says the U.S. is issuing an emergency order grounding all Boeing 737 Max 8 and Max 9 aircraft in the wake of a crash of an Ethiopian Airliner. (AP Photo/Ted S. Warren)

In this photo taken Monday, March 11, 2019, a Boeing 737 MAX 8 airplane being built for TUI Group sits parked in the background at right at Boeing Co.'s Renton Assembly Plant in Renton, Wash. Britain, France and Germany on Tuesday joined a rapidly growing number of countries grounding the new Boeing plane involved in the Ethiopian Airlines disaster or turning it back from their airspace, while investigators in Ethiopia looked for parallels with a similar crash just five months ago. (AP Photo/Ted S. Warren)