What air-traffic control's worst problems for 25 years mean for your flights

Independent

14-07-2025

UK holidaymakers are experiencing what are said to be the worst air-traffic control (ATC) issues in 25 years – with 30 million passengers expected to be delayed this summer.
Airspace closures over eastern Europe and chronic staff shortages at air-traffic control have been exacerbated by strikes by controllers, notably in France.
One million airline passengers were hit by a strike by French air-traffic controllers in early July, according to the pan-European aviation coordinator Eurocontrol.
Ryanair is now running an online 'ATC League of Delays' which is topped by France, Spain and Germany. The best-performing nation is Ireland, where the airline is based. Ryanair says: 'ATC delays will now be even worse in summer 2025."
What does this mean for your holiday schedule – and what are your rights if your flight is heavily delayed or even cancelled?
What's the problem with air-traffic control?
Capacity is constrained like never before. The number of flights scheduled in Europe is almost back to pre-pandemic levels. According to figures released this month by Eurocontrol, the total is now 98 per cent of summer 2019 levels.
But the available airspace has been drastically reduced because of the Russian invasion of Ukraine – whose skies are closed to passenger traffic. Western airlines are banned from Russian and Belarus airspace. As a result, hundreds of flights each day between Europe, the Gulf and Asia are routed through constrained airspace, competing with normal holiday traffic.
Summer storms make matters even worse, closing down yet more sectors of the sky.
An even bigger and wider problem is a shortage of controllers, especially at 'area control centres' – which look after large chunks of European airspace.
Some air navigation service providers (ANSPs), especially in France and Germany, have one post in four unfilled.
What is the cause?
The Covid pandemic is mainly to blame. A series of issues combined to leave ANSPs chronically short of staff.
The deep slump in aviation during lockdowns in 2020 and 2021 hit providers hard. They earn money from each flight that uses their services. As aviation slowed to almost a standstill, revenue fell to a small fraction of normal times. With no clear end to the imposition of tight travel restrictions and consequent reduction in flying, many experienced staff took voluntary redundancy and left the industry.
New candidates have not been trained in sufficient numbers to replace the departing staff. Early on, organisations were unwilling to invest in recruitment in such uncertain times. But another important reason is the nature of ATC training. This involves staff working in close proximity to one another, which was not permitted at the height of the pandemic.
Selecting and training a controller typically takes 18 months. So even if sufficient controllers were recruited and trained starting now, they would not be in position this summer or next.
Ryanair says things are made worse by the 'hopelessly mismanaged' air-traffic control providers in France, Spain, Germany, Greece and the UK.
What are the locations where delays are most likely?
In the past week, says Eurocontrol, France caused 50 per cent of all delays in the network: 'Hit hard by French ATC industrial action coupled with ongoing capacity and staffing issues.
'This led to severe disruption for passengers, airlines and airports as well as for many air navigation service providers in the network, which had to handle additional demand to limit the overall effects of this disruption.'
The next two, Spain and Germany, both contributed 10 per cent of delays, due to 'capacity issues and weather'.
Earlier in the year, Eurocontrol revealed the worst area control centre offenders in 2024, together with the contribution each made to the proportion of delays across Europe. There is likely to be a similar picture in the summer of 2025.
What is the effect?
Flights linking the UK with Spain's Balearic Islands, southern Italy and Tunisia are affected by constraints at Marseille.
Eastern France, Switzerland and Italy, as well destinations beyond those locations, are badly affected by staff shortage at Reims.
Direct flight routings from the UK to Croatia, Bulgaria, Greece, Turkey and Cyprus are hampered by staffing problems at Karlsruhe in western Germany and Zagreb. And Budapest delays many of the frequent flights between the UK and Romania.
Network carriers such as Air France, KLM and Lufthansa are susceptible to delays because so many passengers are connecting through their hubs in Paris CDG, Amsterdam and Frankfurt respectively. With transfer times of an hour or less between flights, a delayed arrival can trigger many missed connections.
Ben Smith, chief executive of Air France-KLM, said: 'The shortage of air-traffic controllers [in France] is 20-25 per cent which means many of our flights are going to be delayed.'
Low-cost airlines are affected differently. They typically allow only half-an-hour to 'turn" an aircraft between arrival and departure. If there is a delay to the 'first wave' of flights going out in the morning, the impact can reverberate – and worsen – during the day.
What is the best strategy to avoid undue delays?
When booking on network carriers – including Gulf-based airlines such as Emirates and Qatar Airways – try to allow more than the minimum connection time.
On budget airlines, the 'first wave' of flights will normally get away eventually; on a recent early departure on the short hop from Gatwick to Strasbourg in eastern France, I was delayed an hour waiting for an air-traffic control slot. A similar wait on the return leg can mean that even UK domestic flights are delayed, if the plane is stuck abroad.
Early to mid-afternoon can be relatively unaffected, because many airline build in 'fire breaks' designed to allow them to make up time. This also has the advantage that UK airports are much quieter than during the first wave.
But later in the day, there is a risk that air-traffic control delays can lead to flight cancellations if the destination – or starting point – has a curfew on night flights.
What about strikes?
Summer 2025 has started extremely badly, with Greek, Belgian, Italian and especially French air-traffic controllers flexing their industrial muscles.
The strike in France in early July cancelled the flights of 200,000 passengers and is estimated to have cost the airlines more than £100m.
One in three of all flights in Europe fly to, from, within or over France, making them extremely susceptible to industrial action by controllers.
Can anything be done to sort out this mess?
Yes. The Single European Sky (SES) initiative, launched in 1999 would remove national airspace boundaries and rationalise the skies. Far fewer controllers would be needed. Compared with 2004, the European Parliament says SES 'could triple airspace capacity, halve the costs of ATM [air-traffic management], improve safety tenfold and reduce the environmental impact of aviation by 10 per cent'.
But the pace of process has been glacial, with obstructions to the removal of barriers by authorities and trades unions in a number of countries. While this lamentably delayed project remains moribund, passengers will continue to be told by pilots, 'We have to wait on the ground here for an hour for a slot'.