I realize this completely off topic. That is why I am posting this here. As one who looks at flight data quite often, I am curious to know where the "supposed" data comes from that resulted in the grounding of the 737 Max 8. Being that the flight recorders have yet to be analyzed from either of the 2 crashes, where does this "supposed data come from, that would lead to this? I have seen numerous reports of pitch angle deviations during flight, presumably shortly after takeoff. As far as I am aware there is no telemetry transmitted from each individual aircraft to a ground station. Radar data, and or satellite data are iffy at best in an analysis of this sort. Can someone explain where this data originates? Or is there any "firm" data that would support the grounding of the aircraft other than the actual flight recorders? This has me intrigued, as to the reasoning. Not to say it is a bad thing. Far from that, but I am very curious as to the "origin" of the data that led to the grounding.