A device for evaluation of the operational capabilities of an aircraft for informing a user about the capabilities of the aircraft to carry out a mission. Included are means for detecting malfunctions of aircraft equipment adapted for functioning during a mission. An evaluation device includes means for acquisition of information about the mission; a means for calculating observed feasibility level of the mission on the basis of at least one detected malfunction and the information obtained about the mission of the aircraft; and a means for presenting a synthetic reactive indicator, representative of the observed feasibility level of the mission in at least one instant of the mission. The means for acquisition, calculation and presentation are adapted for functioning during the mission, to inform the user about the observed feasibility level of the mission depending on the detection of new malfunctions and/or the modifications of the mission in course.