Comment by nine_k
2 days ago
Is this a switch that has a dedicated connection to the corresponding cutoff valve? Or does it go through some common digital bus that passes commands? If so, how well is this bus protected?
2 days ago
Is this a switch that has a dedicated connection to the corresponding cutoff valve? Or does it go through some common digital bus that passes commands? If so, how well is this bus protected?
Another commentator has pointed out that the flight data recorder records two signals - one for the switch itself, and one for the actual valve movement.
I take your point that we should always be suspicious of complicated, digital buses, and this is not the final report, so there’s still plenty of time to uncover weirdness. However, if the flight date reporter shows the switch being thrown, and then a few milliseconds later, shows the valve starting to close, and the same sequence happening shortly there after on the second switch and valve, I feel this would really limit the likelihood of any digital shenanigans.