I worked next to the engineer that was developing a "tandem" system for head boxes. The standard chute head box held two chutes, yes two chutes a round for initial ejection so the pilot could safely survive and ejection. The other chute was a ram air. The pilot had the option to "cut away" the round so he could maneuver to a safe area and land further from the wreck. If you are still wondering how one could fit two complete functional chutes in a head box...that’s why he got paid the big bucks.