The Brazilian Airspace Control System against Unmanned Aircraft Systems is a strategic issue that can become a target of new 21st-century threats due to its importance for civil aviation and the Brazilian Aerospace Power. The characteristics of this new device involve its low detection rate by radars and the ineffectiveness of traditional air countermeasures systems in its confrontation. The scrutiny is performed from the perspective of Capability-Based Planning, as it provides more rationality for decision-making on future acquisitions and makes planning more responsive to uncertainties, budgetary constraints, and risks. The main objective of this article is to analyze the current perceived capability of the Brazilian Airspace Control System to face and counter the unlawful use of Unmanned Aircraft Systems against this critical national infrastructure. An exploratory-descriptive study, conducted in a qualitative research style, is carried out. However, descriptive statistics are alsoused to assess the results extracted from the application of questionnaires to the Brazilian Airspace Control System managers. The responses indicate that the perceived capability is 74.2% positive,showing that air navigation security operators, on average, consider the measures adopted by the Brazilian Department of Airspace Control to be sufficient and proficient to protect civil aviation and its national aerospace infrastructure against uncrewed aircraft.