At least five observation flights by western spy planes took place over the Baltic Sea on September 7, 2021, ahead of preparations by Russian and Belarusian forces for the 2021 edition of the Zapad exercise.

Every four years, Russia and Belarus conjointly hold military drills called Zapad (“West”). The war games usually take place in several locations around Belarus and Russia, including the Kaliningrad enclave. From September 10, 2021, over 200,000 soldiers, 80 aircraft and helicopters, around 300 tanks, and more than 10 ships will take part in the exercise, according to the TASS news agency. 

Each edition is closely watched by neighboring Poland, the Baltic states, and their allies. This year should be no exception.

According to air traffic open data, on September 7, 2021, the United States Air Force dispatched an RC-135U Combat Sent electronic reconnaissance aircraft from Royal Air Force Mildenhall in Suffolk, northern England. The plane flew a complete circle around Kaliningrad through Poland and Lithuania.

The German Navy sent a P3C Orion maritime patrol aircraft to fly over the Baltic Sea, off the Kaliningrad enclave. 

Two aircraft of the Swedish Air Force, namely a Saab S-100 Argus airborne early warning and control aircraft and a Gulfstream S102B Korpen signal reconnaissance plane, carried out a flight off Kaliningrad as well, though it should be noted that these two operate around that area almost daily.

Finally, a Transall C-160G Gabriel electronic surveillance aircraft of the French Air Force also flew in the vicinity. However, unlike the other spy planes, this one flew between Tallinn, Estonia, and Helsinki, Finland, most likely observing the Russian oblast of Pskov that borders Estonia and Latvia.