VTOLs land while attacking targets near a map boundary

[DARwins1]

Describe the bug
When performing attack runs, VTOLs will occasionally stop moving and drop onto the ground, exposing themselves to ground attacks. This seems to occur most frequently when attacking enemies that are close to the edge of the map.

To Reproduce
Steps to reproduce the behavior:

1. Grab some VTOLs (ideally ones that are capable of multiple attack runs)
2. Order them to attack a target near the map's boundary
3. Notice how some VTOLs will drop out of the sky during their attack runs (this seems to happen right at the edge of their run, right as they would normally turn around for another run)

Expected behavior
VTOLs should not land while attacking under any circumstances.

Screenshots or Videos

Additional context
I'm pretty sure is related to this code block in action.cpp.