This is an extremely rare event being carried out in recognition of Poland's acquisition of dozens of F-35 fighter jets. 

An Air Defense Identification Zone (ADIZ) encompasses a 30 NM radius (35 mi; 56 km) circle centered on the Ronald Reagan Washington National Airport (DCA). 

Within the ADIZ is an even more sensitive zone designated the Washington, D.C. Metropolitan Area Flight Restricted Zone (DC FRZ). The DC FRZ extends approximately 13–15 NM radius (15–17 mi; 24–28 km) around DCA.

Within the DC FRZ are Permanent Prohibited Areas including the airspace above the U.S. Capitol, White House, and Naval Observatory.