NATO Airborne Warning and Control System (AWACS)
NATO AWACS play a unique role for the Alliance by conducting airborne early warning and control capability (C2).
Following Russia's annexation of Crimea in March 2014, NATO has assigned its E-3A AWACS aircraft to surveillance flights over eastern member states, as part of NATO efforts to reassure these states, monitor the crisis in Ukraine, to enhance situational awareness and reinforce its presence over the Alliance's territory. Since October 2016, NATO AWACS have also provided air surveillance and situational awareness to the Counter-ISIL Coalition. Their capabilities allow the aircraft to monitor Iraqi and Syrian airspace by flying over international and Turkish airspace.
The NATO E-3A Component is the backbone of the NATO Airborne Early Warning & Control Force (NAEW&CF) which is comprised of two components: the E-3A and E-3D aircraft. Fifteen E-3A aircraft are based in Geilenkirchen, Germany and at the operating airfields in Greece, Italy, Turkey and Norway. Six aircraft of the UK E-3D fleet are based in Waddington, UK.
To know more about NATO AWACS and the NAEW&CF, please check out their website here