Boeing was close to software fix before second 737 Max crash

Boeing was agonisingly close to a software fix for its 737 Max jetliner when an Ethiopian Airlines jet plunged to the ground March 10, the second deadly crash in less than 5 months. The planemaker, working with regulators, has spent months refining the feature since flight data from the October crash of a Lion Air jet in Indonesia indicated that the flight-control system had repeatedly tipped the nose down before pilots lost control. The upgrade proved more complicated than the manufacturer initially estimated, according to a Boeing executive. Among the challenges for Boeing flight-control engineers is girding against “unknown, unknowns,” the random and unlikely circumstances that could cause the so-called MCAS software to again overwhelm pilots, said Mike Sinnett, a Boeing VP of product strategy and development. <br/>