OpenSky Report 2021: Insights on ADS-B Mandate and Fleet Deployment in Times of Crisis

The year 2020 had been selected by EU and US regulators as the deadline for ADS-B compliant Mode S transponders, following various iterations of ADS-B and Mode S services. It will also be remembered as marking a profound change in civil aviation, when the global virus outbreak triggered an unprecedented slowdown in traffic and brought immense impact on the world economy. Fleets have been grounded and a great number of airplanes went into long-term storage due to travel restrictions. The OpenSky Network has been collecting valuable information regarding ADS-B compliance since 2017. It also acted as an important open data source for studying the aviation industry during these crisis times. In this paper, we analyze years of data collected by the OpenSky Network to provide an overview of the past and current situations in global air traffic with equipage updates, ADS-B implementation, Mode S interrogation practices, and fleet management by airlines.