NATO: What is Air Defender 23? Where is it taking place? How long will it last? How will it affect Gatwick Airport? Which routes will be affected?

Holidaymakers across Europe face nine days of potential delays due to the ‘largest deployment exercise of air forces in NATO's history’.

But what is Air Defender 23? And how will it affect Gatwick Airport? Here’s all you need to know.

What is Air Defender 23?

The Air Defender 23 exercise, which started today [Monday, June 12] and is hosted by Germany, will see 10,000 participants and 250 aircraft from 25 nations respond to a simulated attack on a NATO member country.

The Bundeswehr [German defence force] said: “The goal is to exercise air operations with allied air forces. The focus is on optimizing and expanding cooperation among participating nations. The scenario is modeled on a NATO Article 5 assistance scenario.

“The exercise was initiated by Germany in 2018, planned out in subsequent years and will take place in the summer under German leadership.”

Article 5 means: ”If a NATO ally is the victim of an armed attack, each and every other member of the alliance will consider this act of violence as an armed attack against all members and will take the actions it deems necessary to assist the ally attacked.”

Air Defender 23 has also been widely seen as a message of deterrence to Russia following last year’s invasion of Ukraine.

How long will the exercise last?

Air Defender 23 runs from Monday, June 12 to Thursday, June 22 – although no exercises will take place on the the weekend of Saturday, June 18 and Sunday, June 19.

How will Air Defender 23 affect passengers at Gatwick Airport?

Civilian pilots have been told to navigate around three ‘clusters’ of Germany where flights are either restricted or forbidden.

These areas will be closed or restricted for commercial aircraft for several hours each day.

The three ‘clusters’ are:

– North: Which includes North-West Germany, the Netherlands and Denmark.

– East: Which includes East Germany and runs close to the borders of Poland and Czechia.

– South: Which includes South-West Germany and Luxembourg.

Deutsche Flugsicherung [DFS], the German air-traffic control provider, has said flight disruption will be ‘unavoidable’ during the NATO exercise.

A statement on the DFS website said: “Civil flights will be re-routed where necessary and given fixed take-off slots. If the planned number of flights exceeds the acceptable capacity set for air traffic control, delays may occur.

“Simulations by the European Organisation for the Safety of Air Navigation (EUROCONTROL) suggest that flight cancellations are not to be expected as of now. Flight delays and longer flight times, on the other hand, will be unavoidable. This is due to the expected dynamic nature of this unique large-scale exercise as well as the existing complexity of the system.

“DFS will increase its staffing to an exceptional extent during the exercise. Airlines and airports were provided with all relevant information at an early stage. They have adjusted their operational planning and ground processes to fit the situation as far as possible.

“Together with all partners in the air transport system, DFS will do everything possible to minimise the impact on civil air traffic.”

A further statement on the Bundeswehr website said: “All parties involved, first and foremost the German Air Force itself, German Air Traffic Control, Eurocontrol, airlines and airport operators, are doing everything they can to keep the impact of Air Defender 23 on the population as low as possible.

“For example, the three air training areas are only used for military purposes at staggered times and never simultaneously for up to four hours a day and are not available to civil air traffic during this time window.

“In close cooperation with the authorities responsible for air traffic control, the airlines and the civil airports, processes and procedures are currently being optimized to minimize the impact on civil air traffic as far as possible.

“The latest results of the last simulation by Eurocontrol on the impact of Air Defender on civil aviation have shown that no flight cancellations are to be expected, but at most delays. Please direct individual inquiries regarding the impact on civil air traffic to your respective airline.”

Which routes will be affected?

Simon Calder, travel writer for the Independent, said: “The South cluster will have a significant effect on many holiday flights. Departures from London to Antalya in Turkey normally fly right through this sector, as do aircraft from Manchester to the Greek islands.

“It will also impact Lufthansa’s main hub, Frankfurt. Further north, flights to Berlin, Poland and Denmark could be impacted

“On top of some planes flying longer routes, Eurocontrol has also warned that the average en-route delay expected for each flight as a result of the exercise is between 150 and 180 seconds. Again, that may seem trivial.

“But with budget airlines such as Ryanair timetabling flights with just 25 minutes between arrival and departure, air-traffic control delays can swiftly build and affect schedules.

“The German government has asked individual states to relax their airport curfews during the exercises in case delays build up.”