The expected number of airplanes flying is increasing every year. By 2025, U.S. commercial air carriers are projected to fly 2.1 trillion available seats per mile and transport 1.3 billion passengers for a total of 1.7 trillion passenger miles. Furthermore regional carriers are growing faster than mainline carriers (3.8 vs. 2.8 percent a year). This means that if aviation safety does not keep improving, the accident rate will probably increase.

Furthermore, studies show that at least 20% of the root causes of accidents arise in the design stages and when safety problems are discovered later on, they are often difficult and expensive to be resolved.

For these reasons, a methodology has been developed which enables the evaluation of conceptual aircraft design from a safety point of view. It is an approach for conducting a structured analysis which can assess and quantify safety and risks of design features for conceptual aircraft design.

In this paper it will be shown that the most important advantage of this methodology is to allow designers to evaluate and compare the total effect of different design options on safety during the conceptual design of aircraft.