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Pilot And Crash Dynamics

A pilot needs some understanding of the mechanics of crash injuries if he is to make the wisest decision in a forced landing situation that looks grim at best. The following discussion is intended to give this understanding, without getting involved in the medical and engineering aspects of the subject.
Crash injuries, like aircraft damage, are the result of the violence generated by sudden stoppage and fall into two broad categories.
Contact injuries, resulting from forceful contact between occupants and environmental structures. This is the most common form of injury during forward decelerations, when the occupants do not use an adequate restraint system (seat belt and shoulder harness). Injuries caused by loose objects in the cockpit/cabin area also fall into this category.
Decelerative injuries. Although all contact injuries involve a deceleration process, the term decelerative injuries is generally used to indicate bodily damage resulting solely from loads directly applied through the occupant's seat and restraint system. They affect the body internally, and one of the characteristic forms is spinal injury during vertical decelerations (excessive positive G). Internal injuries caused by seat belt impact in the lower abdomen may occur during severe forward decelerations, especially when the seat belt is not properly installed or used. (Note: The seat belt should cross the hips at about a 45-degree angle, and the buckle should be worn as low as possible so that decelerative loads are applied to the hip bones and not the soft abdominal area.)
Injuries resulting from post-crash complications form a separate category. In the event of fire or during ditching, fuselage distortion and final aircraft attitude may interfere with the timely evacuation of the wreckage. Although this hazard can be controlled to some extent by the design of fuel systems and emergency exits, it is often the pilot's landing technique and his knowledge that govern the post-crash...