In the period from June 12 to 23, 2023, the European NATO countries are conducting a large-scale air force exercise under the project name "Air Defender". Due to the fact that "restricted areas" are also being declared over Germany, this will have an impact on Switzerland's largest airport.

In consultation with the Federal Office for Civil Aviation, Zurich Airport has announced that special permits for take-offs and landings may be issued up to 00:30 a.m. at the latest. However, the prerequisite is that the flight is delayed due to the NATO exercise. It is currently difficult to estimate how badly Zurich Airport is actually affected by military training. Passengers will be informed by their airlines about any changes in flight times.

For the largest exercise in the history of NATO with more than 200 military aircraft from 25 nations, three exercise airspaces will be set up in German airspace, which are alternately closed to civil air traffic for several hours a day. The airspaces are closed during the exercise period from Monday to Friday and are sequentially distributed throughout the day. The NATO exercise leads to traffic intensification and flight diversions and thus to capacity bottlenecks in Europe in general. At the same time, the number of delayed flights will also increase in Zurich due to the need to fly around the practice areas.