The main reason causing fatalities in the event of an air crash is head injury as a result of head impact of occupants to surrounding items in the cabin interiors. Aircraft cabin interiors are divided using bulkheads and head impact with these obstructions form one of the major factors to study the physical measure Head Injury Criteria HIC. This thesis presents a parametric study conducted on the head paths and head trajectories during a crash using the Federal Aviation Regulations FAR Part 25 and Part 23. This thesis also presents a parametric study of the properties of the bulkhead, the seat belt, the friction and the seat pitch, and how its variation affects the HIC value and the trajectory of the head paths. The attempt is to find the ideal set of properties so as to minimize the HIC value.