What procedure is followed if VMC formation flight is not possible?

The appropriate procedure when VMC (Visual Meteorological Conditions) formation flight is not possible is to rejoin through a holding pattern. This approach is a safe and tactical method to regain contact within the formation, as it allows each aircraft to maintain safe separation while waiting for conditions to improve for visual flying.

Utilizing a holding pattern ensures that all aircraft are operating in a defined area where they can constantly communicate and maintain situational awareness. Within the pattern, you can manage your position and timing to safely rejoin with other formation members once clearance and visibility allow it.

The other options might involve risks or may not provide a structured environment for rejoining, which is critical in formation flying. For instance, rejoining in IMC could lead to increased chances of disorientation and potential mid-air collisions due to lack of visual references. Splitting the formation may not be necessary and could complicate the situation further if not managed properly. Proceeding directly to the entry point does not allow for adequate control of formation integrity and can also lead to operational disarray. Therefore, using a holding pattern is the most disciplined option to facilitate a safe rejoining of the formation.