Holiday stories – how was the summer for Europe’s airports?
With the Summer Olympics well behind us and the Autumn now upon us, it is time to check up on airports and assess their performance during Summer 2024. With traffic numbers almost recovering fully back to 2019 levels, significant weather disruptions, and heat records, this summer has presented many challenges.
Analysis by Daniel Skoglund from Swedavia, chair of the ACI EUROPE Airport Performance & Capacity Steering Group, and Jeffrey Schäfer from Schiphol, Chair of the ACI EUROPE Airport Performance Network1.
Comparing performance: 2024 vs 2023
During the summer period, from May – August 2024, at the 30+ airports which form ACI EUROPE’s Airport Performance Network, 67% of flights arrived and 58% departed on time2. In the same period in 2023, 66% of flights arrived and 57% departed on time, highlighting a status-quo situation.
However, while the percentage of delays remained roughly the same, there is a significant difference between the circumstances that lead to the flight delays.
The main operational challenges for European airports
Runway and airspace congestion
The prevailing issues were linked to, most notably, congestion at airport runways and airspace. These delays forced flights to hold on the aircraft stand awaiting departure clearance, thus also blocking the stand for subsequent arrivals. This not only delays the aircrafts directly landing or departing but causes a snowball effect in the tight scheduling of flights. The combination of these delays further deteriorated punctuality as the turnarounds and transfer of onward bags, cargo and passengers were also delayed at the hubs.
Airspace-related (ATFM) delays and regulations have increased significantly compared to summer 2023. This is partly due to airspace overdemand, but also due to adverse weather conditions increasingly hampering the flow of aircraft through central European airspace.
Additionally, while the number of flight movements broke even with 2019, the size of our usable airspace is significantly smaller due to the war in Ukraine and subsequent impact on European airspace usage, further increasing ATFM delays.
In the quite technical (we know, sorry) graph it’s visible that during this summer (in red) the number of daily delay-minutes endured by flights in European airspace is significantly more than 2023 (in green).
These spikes of delays are due to special events – such as the Paris Olympics and UEFA EURO 2024 – taking place, but also because of regular peak summer travel demand, i.e. not caused by anything out of the ordinary.
This sequence of flight delays highlights the importance of good collaboration and the need for further integration of air traffic control, airline, and airport operators in Collaborative Decision Making processes.
Severe weather
The severe weather over Central Europe this summer caused significant airspace restrictions, on top of the familiar flow regulations which were present as usual, also causing significant delays from the first morning wave onward for multiple airports.
In particular, the central to Southeast Europe corridor (between Austria and Greece) has had to endure severe restrictions due to weather, on top of the usual peak-capacity related delays.
One observation multiple airports highlighted was that when certain sectors experienced severe weather and had to regulate or re-route traffic, the surrounding sectors also significantly reduced capacity to prevent overdemand in their sectors. This process resulted in cascading delays on flights which were operating totally outside the (truly) affected airspace sector.
The most significant effect from all delays comes from the snowball effects. For example, when a flight lands at its destination delayed, the handling agent often isn’t present at the stand on-time to park the aircraft on-time. Additionally, the knock-on effects on transferring passengers, bags and cargo is affecting countless onward flights at the hub airports.
Saving the day in the morning
Significant emphasis has been placed by ACI EUROPE, EUROCONTROL and IATA on prioritising first rotations – as in, the first aircraft to depart each day – to mitigate knock-on delays throughout the day this summer and enhance the off-block punctuality targets set by most airlines and airports. While this strategy effectively reduces knock-on delays, it has also introduced challenges, sometimes resulting in early arrivals. These early arrivals create greater operational complexity at the destination airport, as the expected demand arrives before the necessary capacity is ready, necessitating re-planning and affecting actual on-time arrivals.
Early is not always good
An increasing problem is the long standing issue of flights arriving too early. A large number of flights, especially in the morning, arrive significantly (15-30 minutes and more) before their scheduled arrival times, triggering unforeseen peaks at airports and the surrounding airspace, which puts pressure on the airport operation and in turn delays other flights. While the purpose of this is to reduce delays, it can often have the opposite effect – increasing them for later flights.
How can we structurally improve punctuality?
Improving punctuality is an obligation towards our passengers and serves the quest for efficiency in operations. ACI EUROPE’S Airport Performance Network (APN) identifies two key action points to achieve better results:
- Collaboration must be fostered, especially in times of great challenges: not only airport to airport, or between the EUROCONTROL Network Manager and airports, but collaboration is also key among airlines, airports, ground handling agents and Air Navigation Service Providers. With delays having a knock-on effect for all parties involved, those parties must work together to mitigate the challenges and ultimately lessen the burden of delays.
- Technological harmonisation must be increased: Technological transition is an imperative in this day and age. We therefore call for harmonisation efforts, based on sharing of best practices and standards, in order to expedite innovation and drive up operational performance across Europe.
There is always room for improvement, especially in driving up punctuality, which is one of the reasons why ACI EUROPE’s APN has begun publishing monthly punctuality reports. These are drawn from a sample of key airports across Europe and can be used to observe the evolution of arrival and departure punctuality, determine the reasons for specific shifts in performance, and to begin managing and improving performance. A proactive and coordinated approach based on information sharing between stakeholders is one of the key means in ensuring such improvement, which has clearly shown its merits this summer. We now must uphold this as the standard for the summers to come.
1 See https://www.aci-europe.org/component/attachments/attachments.html?id=2538 for a list of these airports.
2 All flights are considered to be punctual when they are delayed up to 15:59 mins.
