The air transportation industry has undergone unprecedented changes throughout the COVID-19 pandemic, as measured in terms of flight cancellations, aircraft retirements, airline bailouts, and disconnection of worldwide communities. In this study, we performed a cross-comparison of the impact COVID-19 had on three aviation centers of the world—the United States, Europe, and China. Methodologically, we analyzed the air transportation system as complex networks and by using time series analysis. We discovered that the peak of COVID-19 impact was around April/May 2020, followed by a strong recovery mostly in domestic subsystems. We found a homogeneous impact on the United States, a strong heterogeneous impact on Europe, and a rather short-term impact on China. Domestic flight connectivity recovered much faster than international flight connectivity, particularly for the Chinese air transportation system. Our study provided a comprehensive, data-driven analysis of the COVID-19 impact on air transportation for these three major regions, augmented by references to the rich scientific literature on this subject. We hope that our work opens up pathways to a better understanding and a higher degree of preparedness for future pandemics.