The lawsuit was filed in Chicago federal court by the family of Jackson Musoni, a citizen of Rwanda, and alleges that Boeing, which manufactures the 737 MAX, had defectively designed the automated flight control system.
Boeing said it could not comment on the lawsuit.
“Boeing … is working with the authorities to evaluate new information as it becomes available,” it said, adding all inquiries about the ongoing accident investigation must be directed to the investigating authorities.
The 737 MAX planes were grounded worldwide following the Ethiopian Airlines disaster, which came five months after a Lion Air crash in Indonesia that killed 189 people.
Boeing said on Wednesday it had reprogrammed software on its 737 MAX to prevent erroneous data from triggering an anti-stall system that is facing mounting scrutiny in the wake of two deadly nose-down crashes in the past five months.