Simple status feedback.
I am an electrical engineer with considerable experience in highly automated equipment that can kill people when things go wrong. Hence I am highly interested in these discussions about the plane’s automation. I have very limited flying experience.
A reason for the AF447’s pilot illogical behavior has been given as the “startle factor” or “information overload” The key trigger for this was the mode change to alternate law, At this point recognition of a stall was unnecessary because the plane was not stalled. The UAS was the trigger for the mode change but the UAS was recognized by the pilots. What appears to have been misunderstood was the consequences of the mode change. If the pilot recognized that the mode change disabled the AOA protection and the consequences having no AOA protection I do not think he would have pulled the stick fully back prior to the plane becoming stalled.
The plane was in a non optimum state, the computer recognized this state and implemented some counter measures to supposedly keep the plane flying. The key counter measure (from my very limited understanding) was removing the AOA protection and handing the elevator control over to the PF who supposedly with his superior senses and analytical skills can continue flying the plane with feedback from various other sources including the computer. However his ability to cope with the situation is dependent on how well he understands the situation from his prior training, what he can decipher from the environment and what the computer is telling him.
A modern computer has a lot of processing power and lots of available memory allowing for a complex program. With a complex computer program, when there is a reversion to “manual mode” better feedback indicating the status of the equipment (an aeroplane in this case) as seen by the computer is required. Note, I am referring to the computer status. While feedback of the PF’s physical body status can be determined better with control columns what I am talking about is the status of the plane as seen or determined by the computer. With simpler programs indicator lights, aural warnings and text messages suffice but as the computer actions get more complex better feedback to the operator (pilot in this case) is required.
In industry we now have better tools for providing such feedback. In complex automated applications we now implement touch screens with pictorial representations of the equipment. A picture contains 1000 words. There appears to be limited pictorial representation of the plane’s status as determined by the computer. In the AF447 case we get messages indicating UAS and a mode change. The pilot has to understand the consequences of the mode change, one of which is the removal of the AOA protection. He must also understand the consequences of the removal of the AOA protection and that the side stick inputs now control the surface deflection and not the G (as far as I understand) and a plethora of other things crucial to the survival of the plane and its contents. Good, simple computer feed back of the status of the equipment from the computer’s viewpoint enables better understanding of the situation and better pilot ability to cope with the situation. In this case a message indicating the mode has changed was announced and it is up to the pilot to know the resulting complex changes to the flight controls. There is a lot of understanding here that the pilot is required to bring to the front of his analytical thinking in a short space of time. What is required in such complex computer programs is good simple feedback to help the operator understand the status of the equipment as determined by the computer. Rather than announce a vague description such as a mode change the pilots need to know exactly what is happening with the controls. In this case the AOA protection (among other things) has been lost. A display with a pictorial view of the plane with the elevators color changing from green to orange would be a good start. This would indicate there is some abnormality with the elevator control and further to this there would be some indication showing the AOA protection is lost etc. This is an example, I am sure a pilot would have better ideas as to how this should operate.
Note, I may have errors in my aeronautical descriptions, which I apologize for but please understand the main point of my post is to highlight the need for better computer feed back as computer programs get more complex when there is a reversion to “manual mode” (alternate law).