NATO’s “Air Defender 23” military exercise to divert and delay hundreds of flights

From June 12 to 22, NATO will conduct the “Air Defender 23” military exercise in Germany. This will be the largest deployment exercise of air forces in NATO’s history. It will involve up to 10.000 participants from 25 nations with 250 aircraft.


“Air Defender 23” raises concerns for airlines operating in and around German airspace. The NATO drill will lead to significant closures and restrictions, resulting in operational challenges for airlines. As a consequence, up to 800 passenger flights will need to be rerouted. This also implies that approximately 40 per cent of flights might face longer flight distances of about 110 km, corresponding to around seven minutes of flying time at cruising speed. While that may sound like a modest impact, the closures will put extra pressure on airspace that remains open. These disruptions are expected to cause delays, prolonged flight times, and potential cancellations for passengers.


Which routes are likely to experience the greatest impact?


Civilian pilots must navigate around three main “clusters” where flying is restricted or forbidden at various altitudes. Each will be closed or heavily restricted for civilian traffic for several hours each day.


– North, extending into the skies above Denmark and the Netherlands.
– East, close to the Polish and Czech borders.
– South, running from Luxembourg along the French frontier, almost as far as Lake Constance


The South cluster is expected to significantly affect numerous holiday flights. Typically, flights departing from London to Antalya in Turkey pass through this area, as do aircraft travelling from Manchester to the Greek islands.


Moreover, Lufthansa’s primary hub in Frankfurt (FRA) will also be affected. Moving further north, flights heading to Berlin, Poland, and Denmark could potentially face disruptions.


Hamburg Airport (HAM) has said that it is impossible to know exactly which individual flights will be affected, due to the unprecedented nature of the exercises taking place. It is, however, doing everything possible to keep disruption to a minimum, and staff have been briefed on how best to manage the situation.


In a statement on the airport’s website, passengers have been advised to monitor the status of their flights and to contact airlines directly for any questions. Stuttgart Airport (STR) put out a similar message.


In addition to planes taking longer routes, Eurocontrol has cautioned that each flight may encounter an average en-route delay of approximately 150 to 180 seconds due to the exercise. Although this may appear insignificant, it can quickly accumulate and affect schedules, especially considering that budget airlines like Ryanair schedule flights with just a 25-minute gap between arrival and departure.


Considering the possibility of delays, the German government has requested individual states to relax their airport curfews during the exercises.


The airspace closures and rerouting of flights necessitate close coordination between military and civilian authorities. The responsible air traffic control agencies must ensure the safe separation of military and civilian aircraft, minimise congestion, and maintain effective communication channels to mitigate potential risks. The rerouting of a large number of flights introduces additional complexities, such as managing increased air traffic in alternative corridors, optimising fuel consumption, and maintaining efficient air traffic flow.


Passengers traveling in and around Germany during the exercise period may experience anxiety due to the possible disruptions. Airlines must communicate proactively, providing timely and accurate information regarding delays, flight rescheduling, and potential cancellations. Ensuring passenger safety and comfort during such situations is of utmost importance. Airlines should also collaborate with relevant authorities to implement enhanced security measures, both on the ground and in flight, to mitigate any potential security risks associated with the exercise.


Geopolitical Context


The exercise takes place in a tense geopolitical context, as the conflict in Ukraine continues to pose a threat to European security and stability. Russia has also conducted and will conduct similar exercises in the upcoming weeks, which involve large-scale manoeuvres of its air and ground forces near the borders of NATO countries. At the end of June, Russia is expected to carry out tactical fighter jet exercises, involving Su-27 fighter jets, over the Baltic Sea with the main goal of testing readiness to perform combat and special tasks operations.


Moreover, the increased military activity in the region also poses a risk of escalation and miscalculation, especially due to the frequent interception of military aircraft by both sides. Interception is a common practice in international airspace, where one state’s aircraft approaches another state’s aircraft to identify it and signal its presence. However, interception can also be seen as a provocation or a show of force, especially if it is conducted in an unsafe or aggressive manner. Therefore, interception can lead to accidents or misunderstandings, as the pilots may misinterpret each other’s intentions or actions. As a consequence, frequent interception of military aircraft in the Baltic Sea region by both Russia and NATO countries is a risk factor that could trigger a crisis or a confrontation between the two sides, with potentially serious consequences for regional security.




The NATO air force deployment exercise, “Air Defender 23,” poses significant challenges for aviation security in and around Germany. The airspace closures and restrictions necessitate close coordination and effective communication between military and civilian authorities. Passenger concerns, safety, and comfort should be prioritised, with airlines providing clear and timely information. It is essential to address the geopolitical context and potential misinterpretations associated with the exercise to prevent the escalation of tensions. Monitoring updates on military exercises and interception of military aircraft should be a priority in order to better assess any signal of (de)escalation of tensions in the area.

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