UPDATE 1-U.S. lawsuit filed against Boeing over Ethiopian Airlines crash

A lawsuit against Boeing Co was filed in U.S. federal court on Thursday in what appeared to be the first suit over a March 10 Ethiopian Airlines 737 MAX crash that killed 157 people. 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.

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.

The planemaker said the anti-stall system, which is believed to have repeatedly forced the nose lower in at least one of the accidents, in Indonesia last October, would only do so once per event after sensing a problem, giving pilots more control. (Reporting by Tina Bellon in New York Editing by Noeleen Walder and Tom Brown)