My limited exposure to aerodynamics textbooks leaves me with the
impression that airflow behind the vehicle is neglected.

When heavy jets came out, there was a spate of light aircraft crashes in
wake
encounters, followed by NASA research and guidance on avoiding.

I have not come across any formulae for air behavior behind aircraft. There

are simply general statements that the air will be descending and vortices

will trail the wing tips.

Perhaps a good analogy for being behind a towplane is that it has
similarities
for approaching a ridge from downwind - a bad place for being slow.