How do airlines adjust their routes to closed airspace?

When tensions rise in various conflicts across the globe, it’s a running joke that netizens swiftly log on to ‘monitor the situation’.

That typically involves loading up X, your favourite news website’s live blog, and, of course, Flightradar24.

As an airspace closes, flights swiftly leave the area, and we end up with a stream of aircraft all following the same route seemingly impossibly close to each other.

But what those tightly packed yellow planes on the screen can’t convey is the amount of work that goes into keeping flights running smoothly, and safely.

How do airlines decide which route to take?

Air routes, or airways, are like roads on a map, with multiple routes between any two city pairs in the world, explains Lindi-Lee Kirkman, regional head of operations, air traffic management and infrastructure for Africa and the Middle East for the International Airport Transport Association (IATA).

Deciding which airway, or road, to take involves numerous factors, such as the weather or reducing emissions, with the most important being safety and security.

“If those two are not met, then none of the other factors come into play,” Kirkman notes.

“An airline always has a safety assessment and a security assessment happening. Whether it’s right in the beginning at the very strategic stage, and then at each part of the process as you go forward towards that flight happening, there are various assessments that happen. They will also have defined criteria that will say ‘go’ or ‘no go’, and each airline has that defined for themselves.”

In some cases, an airspace may not be closed, but an individual airline may decide flying through that area is too risky according to its own parameters, and avoid it anyway.

What happens when an airspace closes

Each individual state has exclusive control over its own airspace, something set out in Article 1 of the 1944 Convention on International Civil Aviation.

If a state decides to close its airspace, a NOTAM (Notice to Airmen) is issued. Airlines will be in communication with both the Air Traffic Controller in charge of the airspace they are currently occupying, as well as the ATCs in neighbouring airspaces to establish where the plane can be directed safely.

While the resulting images coming out of Flightradar24 might seem chaotic, it’s something the aviation industry deals with daily.

“We have demand and capacity balancing as part of everyday air traffic control, that’s not anything unusual,” adds Kirkman.

“You need to have enough controllers within the airspace in order to handle the number of aircraft that are coming through. If there are more aircraft, in other words, the demand is larger than the capacity, then that could be managed tactically.”

Flights could then be spaced out – for example, traffic could be accepted at 10-minute intervals – or an aircraft could be given extra track miles by taking it slightly off course to ensure it is in the air for a little longer than usual.

How the industry deals with conflict zones

Airspace closures vary from complete to partial, and in ongoing conflicts, may last far longer than just a few hours.

Russia’s invasion of Ukraine has seen countries such as Poland, Estonia and Latvia dealing with reduced airspace due to GNSS spoofing and jamming, with other states such as Azerbaijan picking up extra traffic as planes are diverted away from unsafe areas.

Enrico Parini, director of European affairs at the Civil Air Navigation Services Organisation (CANSO), a representative body of air navigation service providers, says that the industry is well equipped to handle geopolitical situations in Europe.

“I think nowhere in Europe, nor anywhere else in the world, was really expecting disruptions at this level,” he says.

“We cannot say that back then we were ready, but we were found ready, because the level of contingency and of resilience that we built previously has allowed us to handle this.

“Unfortunately, we have reached the point where this is basically a standardised situation that we are well acquainted with, and we can execute our activities without ever affecting the safety.”

In some ongoing conflicts, like Sudan, contingency routes have been established which allow aircraft to pass through safe portions of the country, following an atypical route.

By not bypassing the airspace completely, airlines avoid additional hours of flying time, and instead face just a 30-minute delay.

In the Middle East, where conflicts can resume at short notice, establishing contingency routes isn’t always possible.

Instead, if something is likely to arise, a contingency coordination team is established.

Led by the International Civil Aviation Organization (ICAO), this team will coordinate with air traffic control organisations across the affected region as well as the IATA, which will communicate directly with the airlines.

The team will attempt to get as much information as possible in advance so they can know where to expect an additional traffic load, so that individual states can make arrangements to handle the increased demand in advance.

What to expect if travelling during an airspace closure

The main thing to expect if your flight would usually pass through an airspace that is closed is delays, rather than cancellations.

“You wouldn’t necessarily expect cancellations, particularly where something is ongoing,” Kirkman tells Euronews Travel.

“Cancellations generally are not favourable because that impacts everybody. Sometimes they fly longer track routes, so you might find that your flight time is extended, in some cases quite significantly and other cases not so significantly.”

Your first port-of-call for any updates will always be the airline.

“The airline has the passengers’ safety and security top of mind, always,” she adds. “Stay in communication with the airline, to be sure that if there is a delay, you’re aware of it.”