Families of Boeing 737 MAX crash victims file suit against Boeing in Chicago

Boeing said it remains confident in the aircraft and has promised software changes to the MCAS function. "It will be among the safest airplanes ever to fly," read the statement from Muilenburg.

Muilenburg disputed the saying that the 737 MAX was rushed to market. "It was a six-year development; 1,600 test-flights of the airplane; 3,700 flight hours of development on the Max, so it was thorough and it was disciplined," he told investors during a Q&A session at Boeing's annual shareholder meeting in Chicago on Monday.

Outside the Field Museum there were six protestors carrying the photographs of crash victims.

Laurie Engel carried photos of Bennet and Melvin Riffel, two brothers from California of the United States who lost their lives during the Ethiopian Airlines Flight 302 crash. She told Xinhua that she just wanted to raise the awareness of Boeing and "not to put profit before people's safety".

Tarek Milleron, uncle of 24-year-old Samya Stumo who was killed on the Ethiopian Airlines Flight 302, was among the protestors.

The crashes of Lion Air Flight 610 in October 2018 and Ethiopian Airlines Flight 302 in March 2019 made headlines around the world, and finally led to the grounding of the Boeing 737 MAX aircraft by European, Asian and American authorities. Boeing's stock lost 20 dollars per share of value since March 11, the day after the Ethiopian Airlines crash, equivalent to a 5 percent drop in the stock price.

The families' lawsuit was filed in the federal district court in Chicago.