The full turns are performed on the beam following the same technical motions as the floor exercises. The turn is initiated moving the body in one single unit from the head and shoulders to the feet where the back foot not only pushes off the equipment to transfer the body support to the front foot, but also anchors the turning direction during the push off.
This is a fair full turn in a passe position showing a good effort to show a controlled one foot balanced ending. Notice how the turn is created from two feet as the weight support is transferred forward to the turning foot.
Some gymnasts and coaches prefer to begin the full turn from a lunge position, others from a regular step forward, and some like to start the full turn from a fourth position. Here are several passe full turns beginning in a fourth position.