> Because the fault was triggered by specific streams of erroneous flight data, a new software patch can be devised that monitors the computer for that highly unusual condition and prevents movement of the stabilizer when it occurs, one of the people said. Oh man. That sounds like a mess.
As I have mentioned here before: The angle of attack sensor was never intended for the purpose it is now used for - military aircraft may do such things but not as an afterthought and not connected with a control surface which has a lot of delay (trim wheel winding. Delay is a major factor in destabilizing control loops). Equivalent sensors are the airspeed pitot tubes but they are a much more robust concept. Even they have brought down airplanes. We lack sufficient real world (heat, humidity, snow) information about the quality of the sensor data even before it may get distorted by transmission and processing on its way to the control law. Cleaning and validating sensor data is tricky under the best of circumstances. It does not sound like they have a handle on it.
Hi Boeing, what real world data from mounted angle of attack sensors have you analyzed? Why do you believe this data sufficiently represents climate zones and flight conditions (take-off, landing, turbulence, malfunction modes)? How do you clean and validate the sensor data? Please explain, because otherwise I won't step into one of these machines.