This is the first paper in a new series to present a coherent theory of sensing frontal crashes, define the characteristics of future airbag sensor systems and to present examples of how this theory can be implemented. After summarizing the relevant conclusions from the authors' previous papers, this paper concludes that future systems should contain: crush zone sensors which sense relevant impacts to all portions of the vehicle front; an occupant position sensor as an input to the sensing system; and a mechanical safing/arming sensor having a long dwell. It is further concluded that cars should be designed so that only impacts involving the front of the vehicle need be sensed for the deployment of frontal protection airbags.This series of papers has the main goal of determining an overall theory of frontal crash sensing and the resulting desirable properties of sensor systems. A second goal is to give examples of how this theory can be realized in real sensor systems. There is a need for such an analysis as can be seen from the wide variety of sensor systems in use today - it is unlikely that they are all right. In addition several organizations are developing computer algorithms for “Single Point Sensors” based on a variety of different theories. This diversity of systems leads to the conclusion that there is no generally accepted theory of how to sense car crashes.This paper develops a general theory of crash sensing by combining conclusions from previous papers with new analysis and presents a system which conforms to this theory. In later papers in this series, careful analysis will be made of real world crashes to refine the theory and improve the system design.