Boeing Believed a 737 Max Warning Light Was Standard
> But months after the planes were flying, company engineers realized that the warning light worked only on planes whose customers had bought a different, optional indicator.<p>If I am to read this correctly, the angle-of-attack disagree light is installed on all Boeing 737-MAX aircraft.  For customers who did not buy on optional additional indicator, the angle-of-attack disagree light was always off, even if there is a disagreement between to sensors of the angle of attack of the aircraft.<p>Doesn't this seem dangerous in-and-of itself?  If a pilot assumes that the light is off because there <i>is not</i> a disagreement, instead of because there is no information available, she is acting on incorrect information, and might try to address problems unrelated to the actual problem.<p>Also, pilot may switch aircraft and expect the same functionality of safety features and may make incorrect assumptions about the functioning of this light.