nice scene. hovewer, i've noticed you can't deep stall the plane, and that you can succeed then fail the mission(even landing on the dropzone, you can still get the cargo to smash itself at the nearest mountain). also, it looks like the wheels get destroyed when landing outside of the airfields.
funny fact: i've managed to land even without the wing(too steep descent, tried to correct it and went too harsh on the controls, then the engine attached to that wing worked as a brake, allowing me to land)
use CSG instead of a grid to make the heads. lower end of the barrel is a polygon, better to put that catch somewhere else, and turn it into a box. also, for your specs, the gun is overpressured. there is no ejection system, and recoiless catridges wont work well with this design. also, you might want to use a DA-styled revolver action for the trigger
you can edit the scene when you're on your other computer. just log on to your account, get to this scene, and click the edit button. there, you can upload your scene with the better ragdoll.