Chaos in the Skies: Heathrow Fire Shuts Down Airport Amid Europe’s Wartime Struggles

Heathrow Airport, the busiest airport in Europe, was shut down following a fire at a single electricity sub-station on the night of March 20. The fire at the North Hyde substation in Hayes, about 1.5 miles from Heathrow in west London, seriously disrupted the area’s power supply, including that of the airport.

The closure has caused chaos, leaving thousands of passengers stranded. According to the plane tracking website Flightradar24, more than 1,300 flights have been affected. About 120 of these were already in the air.

Below, a panel of experts offer their insights – and consider the implications of such a major incident. (Elements of this panel were sourced by the Science Media Centre, which published a version here.)

Power in West London is highly constrained

Barry Hayes, associate professor in electrical power systems, University College Cork

A transformer fire in the North Hyde 275kV substation apparently caused the power outage (videos from the scene clearly show one of the large power transformers ablaze). This sizeable electrical substation supplies the area northeast of Heathrow Airport and the Heathrow Airport site. Scottish and Southern Electricity Networks, the local electricity distributor, said 67,000 homes and businesses in the area were cut off overnight due to this issue.

While the North Hyde substation is an important part of the West London electricity grid, it is generally not expected that this would cause such a big impact at Heathrow Airport. There are also dedicated supplies to other parts of the airport site.

A critical electricity load such as Heathrow would typically be served from multiple supply points in the electricity grid. Therefore, there would be an option to feed the loads at Heathrow from an alternative supply point. Some reports show that parts of the airport (Terminal 5) have power.

The exact reasons for such a significant impact are unclear at this point. Still, we know the North Hyde substation is in a highly constrained area of the UK electricity grid. In this area, there has been “a steep increase in the number of new electricity connection requests across west London, driven by new housing developments, commercial investment, and data centers.”

The UK power grid (as in many developed countries) is generally old or outdated, with many components at the end of their anticipated service lifetime and urgently needing modernization. These issues may be a factor in the power outage affecting Heathrow. However, it will take some time before the exact causes of this incident are established.

Weather, aging equipment, or malicious attacks could be to blame

Chenghong Gu, professor in smart energy systems, University of Bath

This is a very rare event. Substations are built and operated according to stringent standards and monitored 24/7. There are also many automatic devices in substations like this one to deal with faults.

A substation has many components, including transformers, circuit breakers, an isolator, busbars, and measuring equipment. Transformers are the most vulnerable to fire. They contain insulation oil, and in high-temperature, high-pressure situations, they can explode, meaning the insulation oil leaks and can catch fire.

However, it is very unusual for big substations like this to catch fire. One cause can be extreme weather, such as lightning strikes, which could cause extremely high voltage on the equipment. Extreme hot weather and high demand can also cause transformers to become overheated, thus leading to faults.

Another factor is transformer aging. The insulation gas can degrade, which could cause an explosion inside a transformer. Other auxiliary devices, such as the insulator, switch gears, or circuit breakers, could malfunction inside the substation.

Other possible causes include a malicious attack on the substation—someone setting fire to it deliberately, for example. Cyber-attacks on IT systems can also cause devices in the substation to malfunction, leading to fire.

Serious questions about Heathrow’s back-ups

Kirk Chang, professor of management and technology, University of East London

The airport lost power because of the fire—we understand that. But the backup system didn’t work, and it’s difficult to understand how that could happen.

We need to look at two things. Number one is the technical part. Why did the backup machines not work? Maybe the machines did not have sufficient fuel, or for some reason, the system was not linked to the grid. The backup should kick in immediately.

The second point is more on the human side. Who is responsible for the power management, and what intervention strategies were attempted? If the first fails, I would assume they would need a second backup system. It’s very unusual to see both Plan A (the backup) and Plan B (the backup to the backup) not working.

Usually, a main backup (Plan A) will supply about 90% of the power the facility receives. Plan B will usually only supply a fraction of the power—maybe 50% or 30%. The reason is that Plan B is usually expensive to maintain all the time. It may be outsourced to a third party—either the power company or a software company that manages its power distribution network.

Critical infrastructure arguably needs more security

Paul Cuffe, assistant professor, School of Electrical & Electronic Engineering, University College Dublin

An airport like Heathrow requires a lot of electricity to operate, which is equivalent to a large town. As such, it would be typical for it to be given a dedicated connection from the substation at Hayes.

There is likely a dedicated power line and transformer connecting the airport to the wider grid. When a major fire severs that link, bulk electricity will no longer be possible to bring to the airport.

I anticipate a major airport like Heathrow will have some on-site emergency capability to ride through a grid disturbance. I hope the traffic control tower and runway lights weren’t totally plunged into darkness!

However, processing planeloads of passengers requires Heathrow to consume a town’s worth of electricity in total, and the inability to meet this requirement is probably why the flights had to be canceled.

The failure is not overtly abnormal. We can anticipate that, from time to time, substation equipment will fail, resulting in downstream power outages. But one could argue that a critical piece of national infrastructure like Heathrow deserves special grid connection arrangements to secure its electricity supply further. For instance, sometimes critical loads like this are fed from two separate substations to provide redundancy when outages happen.

It is ultimately a political and economic question to determine the right level of capital investment into grid infrastructure to avoid the problems that outages like this cause. Redundant power supplies for an airport the size of Heathrow do not come free.

Climate change means the grid will face more threats like this

Hayley J. Fowler, professor of climate change impacts;
Colin Manning, postdoctoral research associate in climate science and
Sean Wilkinson, professor of structural engineering, Newcastle University

The closure of one of the world’s largest airports due to the failure of just one electricity substation underlines how important it is that critical national energy infrastructure—pylons, substations, and so on—keeps functioning. This is only becoming more important as demand for electricity increases, thanks to transport and domestic heating switching to lower-carbon electrified alternatives—notably electric cars and heat pumps.

Yet the UK’s energy system is facing growing threats from unprecedented risks. We still don’t know what caused the Heathrow fire, but it appears unusual, as threats to energy systems come mainly from extreme weather. In the UK, that tends to mean windstorms, flooding, heatwaves and associated wildfires, and cold spells.

2024 was the warmest calendar year on record, and the “fingerprints” of climate change are increasingly evident in more intense and frequent extreme weather events. It is crucial to ensure the energy network can handle this weather.

Gas and electricity operators in the UK have established protocols for managing networks in adverse weather, investing large amounts to protect critical assets. But recent events have exposed vulnerabilities. The storms Arwen and Éowyn left thousands without power for days, underscoring the previous UK government’s admission that the country is underprepared for extreme weather events.

Kirk Chang, Professor of Management and Technology, University of East London; Barry Hayes, Senior Lecturer (Associate Professor) in Power Systems Engineering, University College Cork; Chenghong Gu, Professor in Smart Energy Systems, University of Bath; Colin Manning, Postdoctoral Research Associate in Climate Science, Newcastle University; Hayley J. Fowler, Professor of Climate Change Impacts, Newcastle University; Paul Cuffe, Assistant Professor, School of Electrical and Electronic Engineering, University College Dublin, and Sean Wilkinson, Professor of Structural Engineering, Newcastle University

This article is republished from The Conversation under a Creative Commons license. Read the original article.