That's a useful post; excerpting:
Is that the vertical distance? Because the Reaper is subsequently flying to the left, closer to the trail.
There's quite a bit of research on wake vortices. My source is
Holzäpfel, Frank (2005) Aircraft Wake Vortex Evolution and Prediction. Habilitation, TU München . Excerpts:
We could probably compute the vortex descent speed from this, given some assumptions about the speed of the aircraft and its altitude. The weight should be included in the accident report, but depends on the amount of fuel left at the time.
Note from figure 3 and 4 that the area of strong upward air velocity extends beyond the vortices and would affect a light aircraft if a substantial portion of its wing entered that space.
I'm using your diagram to identify the approximate locations of the contrails and vortex centers:
Then I transferred the markings to your screenshot, using the contrails as guide:
I superimposed the
Figure 3 velocity profile in yellow, and the
Figure 4 velocity streamlines in orange. Intuitively, it looks as if the danger zone extends down to the altitude of the drone, even before we consider that the vortex is descending.
If the parts of the Reaper are a CGI addition, but the footage is real, the actual camera platform could have been much farther away, and thus safe from the wake turbulence.