Emergency procedures touted by Boeing in the wake of October’s Lion Air crash "apparently didn’t work as expected" come March. The pilots of Ethiopian Airlines Flight 302 initially followed emergency procedures in killing power to stall-prevention feature MCAS, the Wall Street Journal reports, citing people briefed on preliminary findings due out within days. The pilots then reactivated the system, bucking the standard emergency checklist, likely "because manual controls to raise the nose didn't achieve the desired results." In other words, the plane was still aimed at the ground. With power reestablished, MCAS continued with commands that forced down the nose, even as pilots used electric switches in an attempt to level the jet, the sources say, citing black-box data.
Boeing had issued a bulletin following the Lion Air crash in Indonesia, directing airlines "to existing flight crew procedures to address circumstances where there is erroneous input from an AOA (angle of attack) sensor." If confirmed, the findings "suggest that following emergency procedures in the Boeing handbook may not have been sufficient enough to prevent a crash," reports CNN. Boeing is now in the process of revising MCAS to have it rely on two sensors and grant pilots more control. Last week, Boeing's VP of product strategy said the company had "complete confidence that the changes we're making would address any of these accidents." On Monday, the FAA said there would be "additional work … to ensure that Boeing has identified and appropriately addressed all pertinent issues." (More Ethiopian Airlines stories.)