Air Traffic Management is the complex task of safely managing the flow of aircrafts. This task needs to be solved efficiently to avoid hindering the growth of the aviation sector. Optimization-based decision support tools could assist but, this being a safety-critical and conservative domain, a high level of trust needs to be in place. The amount of trust depends on the level of automation and familiarity with the tools. We argue that this needed trust could best be built if optimization based tools are used in the training of air traffic controllers. We discuss how this training can help air traffic controllers and the model of optimization.