Mr. Craig (Boeing test pilot on early simulator flights), who had been with Boeing since 1988, didn’t like it, according to one person involved in the testing. An old-school pilot, he eschewed systems that take control from pilots and would have preferred an aerodynamic fix such as vortex generators, thin fins on the wings. But engineers who tested the Max design in a wind tunnel weren’t convinced they would work, the person said.
Mr. Craig relented. Such high-speed situations were so rare that he figured the software would never actually kick in.
To ensure it didn’t misfire, engineers initially designed MCAS to trigger when the plane exceeded at least two separate thresholds, according to three people who worked on the 737 Max. One involved the plane’s angle to the wind, and the other involved so-called G-force, or the force on the plane that typically comes from accelerating.
