The Heracles Transporter's cargo pod (which model is used alone on most ground missions battlescape) seems to be ill-attached to the Transporter craft.
Its front side (identified by what looks like a windscreen) is displayed on the transporter's backside, and its backside (the pod's door) is displayed on the transporter's frontside, under the transporter's cockpit.

This had always questioned me, as far as aerodynamics laws are concerned.
Now, what revealed the bug is that on some missions, the transporter craft's model is used on the battlescape on top of the cargo pod's model.
This time, I could took a screenshot for proof of the discrepancy.

'''Suggestion:'''
Correct the craft+cargo pod model in the UFOpaedia (and Craft management screen).