Nowadays air transport has become of one the fastest and safest transportation modes. This article focuses on examining the critical elements of airspace in EUROCONTROL, the organization working to manage European airspace. Regarding air traffic control, airspace is divided into Flight Information Regions (FIR) and Upper Information Regions (UIR), managed by air navigation service providers (ANSPs). This study aims to identify the most critical FIRs and UIRs controlled by EUROCONTROL members. We set two criteria for detecting critical airspace regions: the number of departures and arrivals, and the number of overflying flights. We also set four different time windows, to account for characteristics of air traffic demand. The critical regions according to the number of departures and arrivals criterion correspond with the busiest airport hubs of United Kingdom, Germany and Spain. The critical regions following the number of overflights criterion build a Shanwick Oceanic-Turkey axis where most of the European air traffic goes through, with a bottleneck in Austria and Hungary. These results suggest further directions of research about European critical airspace regions, and new opportunities of building hubs interconnecting Europe and Asia through Central Europe.