No, with system I meant the aircraft as a whole. I meant to say that few things are that obvious if they aren't specified. There should be a point in the risk

No, with system I meant the aircraft as a whole. I meant to say that few things are that obvious if they aren't specified. There should be a point in the risk analysis that handles sensory errors, possible consequences and risk mitigation and if it wasn't specified there, it would have been an error. Go up the chain from there. I doubt that software engineers necessarily know much about the reliability of sensors. You mostly learn that from experience. That is why you should include as much experience in the analysis process as possible. A pilot or the air techs would probably have mentioned the tendency of sensors freezing or having some form of malfunction. Only then can the softies develop a fault tolerant system. After a failure it is always obvious to everyone, but as you said, perhaps they just thought the pilots would notice the error and override the system. Also an obvious assumption that should be documented as mitigation to reduce risk. No risk analysis is perfect, but after the accidents we can expect some diligence and discipline in my opinion and hopefully this accident leads to a review on these processes instead of finding some fall guys. A thorough integration test would probably also have detected the issue at some point and maybe here are faults as well.