The original intent was for the military and the Surgeon General to understand what was causing the high flight mishap rate. Shortly after the appointment of the first flight surgeons, research and experience led to a dramatic improvement in aircrew health as well as a significant raising of the entry medical standards for all aircrew. The early flight surgeons found that the Army's practice of assigning officers to flight duty who were not physically qualified for infantry or cavalry duty was improper. Because of the G-forces, risk of spatial disorientation, and risk of hypoxia encountered in the aviation environment, among other challenges, early flight surgeons found that aviation personnel must be scrupulously healthy and well trained in the basics of aerospace physiology.