Originally Posted by
DaveReidUK
The FR24 "granular data" contains only 18 data points covering the last 2 minutes of flight, from FL290 until contact lost, so about 7 seconds apart on average.
I'd want to see at least 5x as many data points before attempting to draw any conclusions about
the detailed trajectory during the upset.
Theres only 17 valid points for 3D, as one has
no position.
But there is at least 100 points on the straight and level flight before the upset of which everyone is on a perfectly straight line viewed in 3D. No hickups or glitches. Not even a minor imperfection.
There is a 16s gap between the last normal point and the first in the upset. From that mostly 5s gap and I’m sure 5s is close enough when the existing point describe a spiral, to see how the trajectory is in between these 5s gap. For example in a loop you could understand the pull up in the end of a loop with points 5s apart, as the only logic way is the rounded trajectory in between. What we see is a ”about” 1G barrel roll.
Maybe not exactly but not very far from this.
There is a couple of 10s gaps, produced by the lack of a single data point( loss of one per five seconds create a 10s gap between points) but the position of these lost datapoints do not really affect the possibility to understand what happened.
Why, is not that easy though.
The SJ182 initial upset is a carbon copy, the parallel displacement is the same, the initial altitude loss is about the same so the trajectory of SJ182 can be used to understand how Mu5735 got from the fine cruise on level to the first datapoint in the upset.
So we more or less know “what” but we do not have the “why”.