Thanks for posting your code.
Did you derive the system equations or are they from someone's text?
Perhaps your trig ratios for Vdot and Theta dot should be:
\dot{V} = -D/m - g\cos\theta
\dot{\theta} = (L/m - g\sin\theta)/V - \dot{\phi} ?
I've briefly tested your code with the above...
Then I'm inclined to agree with you!
If it was the center of mass, the object would be in rotational equilibrium. If you take your pivot axis at the black dot as you suggested, don't forget to add in the inertia force to produce a torque that counters the torque from the applied force and all...
Hi roldy, good on you for working on your atmospheric reentry project just for fun ;)
It is difficult to assess whether or not your results are 'correct' without seeing how your code fits all the equations together.
Just as an outside observer to your results, your graphs are saying that the...