U.S. air-safety regulators have approved major software and pilot-training changes for Boeing’s grounded 737 MAX jets. The changes are aimed at fixing problems with a flight-control system and implementing enhanced pilot-training using self-guided interactive instruction, according to internal government documents and people familiar with the details, The Wall Street Journal reports. Specifically, the revisions will make an automated stall-prevention feature easier for pilots to control, according to industry and government officials. The stall-prevention system is suspected of causing the fatal dive that killed 189 people on board a Lion Air 737 MAX in Indonesia last October. A team of international crash investigators is also looking into whether the system led to the crash of an Ethiopian Airlines plane less than five months later that left 157 dead. The changes are a reversal of major design principles Boeing relied on when it developed the stall-prevention system.