Passengers, waiting for their flights at Brussels airport (BRU) on September 12, 2018, felt unease when they saw in the sky what looked like an airliner being intercepted by two F-16 fighters. Fortunately, the maneuver was part of a NATO exercise.

While Russia, China and Mongolia was holding Vostok-2018, the biggest military exercise since the Cold War, with more than 300,000 troops and 1,000 aircraft in Eastern Siberia, the air forces of several NATO countries trained over Western Europe.

Fighters including but not limited to French Dassault Mirage 2000 and Rafale, Czech Saab Gripen, Italian Air Force Eurofighter, Spanish Air Force F-18 and even some Croatian Soviet-era MiG-21,  took turn in intercepting an A321 from the Belgian Air Force.

But the exercise scared quite a few people when two Belgian Air Force F-16s were seen escorting an airliner over Brussels Airport. The unusual situation was due to a change of plan, according to Philippe Touwaide, director of the Mediation Service of the Belgian Federal Government for Brussels-National Airport. “The exercise was to be close to Leuven, where it did not bother anyone” said Touwaide to AeroTime via email, adding “because of changing winds, planes flew at low altitude over urbanized areas through the air lane of runway 01, hence the complaints.”

The exercise was part of the Air Policing media flight, and was conducted under the supervision of NATO Air Command in Ramstein, Germany, according to a NATO official. “The Belgian authorities were involved in all the stages of this activity to ensure that this would be conducted in full accordance with safety and environmental requirements,” said the official to AeroTime via mail, adding that the exercise was “organized to illustrate how NATO coordinates and controls the effort to secure Allied airspace through air policing activities. Air policing is a peacetime mission and a collective undertaking which reflects one of the core tasks of NATO, i.e. the defense of all of its 29 members.” Fighters are usually scrambled when a foreign military aircraft is heading towards a forbidden airspace, or when an unauthorized civilian plane fails to answer ATC calls.

In the past, such mockup interceptions were carried out in collaboration with the Russian air force. According to Euronews, the last cooperation with Russia was in 2014, when NATO Eurofighters practiced interception with a Russian Su-27. But this partnership has since been suspended, probably following the Ukrainian crisis.

The main mission of NATO air forces is the Baltic Air Policing mission. Since 2004, it protects Estonian, Latvian and Lithuanian airspaces from incursions, as these countries have no airborne capability of their own. In 2016, no less than 780 interceptions of Russian aircraft were carried out by the Alliance in the region.