It's not the first time a major airport is down because of power failure, and other airports are working to address this type of vulnerability.
> The power vulnerability for airports was never made more obvious and painful than in Atlanta seven years ago. An underground electrical system fire in late 2017 damaged two substations and caused a complete outage lasting nearly 12 hours at Hartsfield-Jackson International Airport
Heathrow's power outage is much worse than Atlanta's, this is really bad. Allow me to make my point:
1. UK’s has one major airport to get out of the country—Heathrow. Gatwick and that lot don’t carry the same weight. When Heathrow goes down, you’re proper stuck. Atlanta has DC, Miami right there.
2. UK allows transit visas, so half the people transiting can’t even step out the terminal, what do they do when the airport is closed?
The US doesn’t allow that, everyone clears customs/passport control, so no ‘no man’s land’ limbo for stranded passengers.
3. Heathrow's outage is going to take 24 hours as of right now. That's twice Atlanta
Both Gatwick [0] and Stansted are busier than either Washington airport [1], and if you're considering Miami as an alternative to Atlanta then why not similarly ridiculous options like Paris, Amsterdam, Dublin for passengers stuck in Heathrow?
Miami and DC aren't even close to the nearest major airport cities to Atlanta. Charlotte and Orlando are many hours closer and busier [1] in terms of commercial passengers (though still not as convenient as the UK's comparable airports).
Only about a quarter of Heathrow passengers are transiting [2] and a significant portion of those are citizens of the US, EU, UK and other countries who don't need a visa. Maybe 10% of passengers are stuck in limbo, not half of them.
1: It's clearly not been as disruptive as you're suggesting. Flights have been diverted to airports within a few hour's journey by bus or train, others have been cancelled, just like would happen with Atlanta.
2: I don't know if they've done it, but the UK can grant entry for a few days to affected passengers. This will be part of a contingency plan.
> 2. UK allows transit visas, so half the people transiting can’t even step out the terminal, what do they do when the airport is closed?
Airside to airside bus shuttle?
> The US doesn’t allow that, everyone clears customs/passport control, so no ‘no man’s land’ limbo for stranded passengers.
Anchorage International Airport, amongst few (less than a handful really) other US airports, have separate international section with sterilised transit.
> It's not the first time a major airport is down because of power failure, and other airports are working to address this type of vulnerability.
To be fair, I'd probably be more interested to hear what major airports are doing to avoid a reoccurance of CrowdStrike-type scenarios. Which is perhaps a more likely re-occurence than loss of substation feeds.
Seems like a national security issue if there’s a single point of failure a few miles away that can take down one of Europe’s largest airports and global air travel.
Military airports are working fine. National security doesn't rely on civilian airports. And communications networks aren't disrupted or anything. This isn't enabling terrorism.
It's absolutely a huge economic issue. Economic-political. But I'm not seeing a national security angle here.
"[...] national security is widely understood to include also non-military dimensions, such as the security from terrorism, minimization of crime, economic security, energy security, environmental security, food security, and cyber-security."
Large-scale issues that impact the economy are typically under the "national security" umbrella. It's a term that uses the broad definition of "security".
Whether this incident qualifies, I don't know, but "national security" is definitely not just about military stuff. Just like how "food security" isn't about physically protecting food from damage.
Amusingly, some media outlets confused the Scandinavian SAS airline with Britain's SAS Special Forces unit, and reported that the special forces unit had cancelled its trips out of Heathrow :) https://amp.theguardian.com/uk-news/live/2025/mar/21/hayes-s...
While I agree that saying this is a big national security issue is overstating it, if an adversary can cripple you economically because you have a few single points of failure, that is a national security issue
“National security, or national defence (national defense in American English), is the security and defence of a sovereign state, including its citizens, *economy*, and institutions, which is regarded as a duty of government.”
Whether mere incompetence from those whose job it is to check such installations for failure or bad actors, other 'bad actors' will have gained a useful indication of how vulnerable Britain’s infrastructure is to attack. It's reckoned > 290K passengers have flights cancelled or diverted and ensuring chaos for days.
Most militarily-significant targets are themselves non-military.
The Russian war of aggression on Ukraine is a prime example: power infrastructure, transportation, communications, commercial hubs, healthcare, and general civilian targets of opportunity are all targeted with high frequency by Russian forces.
UK national security interests are spelled out in summary beginning on page 5 of this PDF, "Government Functional Standard: GovS 007: Security", notably
Each organisation’s governance and management framework shall cover physical, personnel, cyber, incident management, technical and industry security
As an example of non-military focus, the present US national security policy leads with ... tourist visas:
To protect Americans, the United States must be vigilant during the visa-issuance process to ensure that those aliens approved for admission into the United States do not intend to harm Americans or our national interests.
An earlier document from the Bush II White House leads with:
People everywhere want to be able to speak freely; choose who will govern them; worship as they please; educate their children—male and female; own property; and enjoy the benefits of their labor.
Originally conceived as protection against military attack, national security is widely understood to include also non-military dimensions, such as the security from terrorism, minimization of crime, economic security, energy security, environmental security, food security, and cyber-security.
Few people actually include necessary infrastructure into their threat model and almost no one is willing to pay the cost of building effective redundancy into the system. I could probably shut down any airport in the world with a few late-night firebombs tossed into the right substation.
And no, it is not a national security issue. There are three other airports in the London region, plus RAF Norholt and RAF Kenly inside the M25 ring.
I used to live next to RAF Kenley, it's not really usable in any valuable way - it's a relic. It's for gliders only with no powered flight allowed. It has no facilities and is very uneven/roughly paved, but could probably accept landings of small planes or fighters in extremis. Biggin Hill would be used instead if you needed an airport in that immediate area.
> Seems like a national security issue if there’s a single point of failure
No. Its not.
Its the fact that the decades of under-investment in power distribution infrastructure is coming home to roost.
Its no secret there's little to no "fat" in the UK grid system. Hence it has difficulty coping with black-swan events such as this.
Anyone who buys datacentre space in London knows the reason prices have gone through the roof in recent years. Its becasue the grid simply cannot get the extra capacity to where it is needed. And this is before energy prices started rising due to the UK's electricity being mostly dependent on gas (previous governments having sold off gas-storage facilities to build houses on the land instead).
That's why its also a pain in the backside to build new banks of EV fast chargers anywhere in the UK. Getting the power there involves long, protracted, discussions with the grid followed by payments of large amounts of money and a written promise to the grid that you agree to load-shedding at any time if necessary.
I suspect you will find its not a single point of failure either. Its just that Hayes is a high-demand area, so see above for lack of excess capacity .... if one site goes boom, the other will struggle to take on 100% load.
> I suspect you will find its not a single point of failure either. It’s just that Hayes is a high-demand area, so see above for lack of excess capacity .... if one site goes boom, the other will struggle to take on 100% load.
Hayes (North Hyde) is a few miles NE of Heathrow, but Laleham (similar sized) is only a few miles South - I’d would have assumed both served as fully redundant supplies for the airport, given it’s critical national infrastructure.
(The old BBC Television Centre in London had three independent supplies, I believe)
So .. why are people trying to build new datacentre space in London rather than somewhere a bit further away and less expensive? Easier to put the datacentre near the power and run some fiber rather than the other way round, surely?
The expense is unpleasant, but the money has to come from somewhere, and the user paying is easier to justify than all the other bill-payers collectively or the taxpayer.
You keep saying “No it’s not” and then describing exactly what most people would call “a single point of failure” and “a national security issue” in a lot more words.
It's all been privatized and they don't care about anything other than maintaing profits so of course we're seeing the effects now. It's also why every single water provider in the UK is dumping raw sewage into our rivers and when the government tries to make them fix it they cry about how that will eat into their profits and how it's unfair.
If the entire transformer is lost, procuring replacement transformers for substations can take from several months to years. Insulation failures are relatively common in older power substations. It seems someone should have done a better job preparing disaster recovery scenarios for Heathrow.
Edit:
BBC reporting "some power" restored on a "interim basis" as the power company is now using a different substation. It would be curious if the increased effort on other substations would then cause further power failures...A bit like the postmortems of global cloud providers, where taking a node out, causes increased stress on other nodes...
One would hope the utility would have a spare transformer or two sitting around, I guess that’s not guaranteed tho. MV and HV transformers have extremely long lead times like you said.
Yes and no. The vast majority of commercial flights what would have landed at Heathrow today won't be landing at a different London airport instead. There isn't spare, redundant capacity for that. Instead the flights will be cancelled.
What would you suggest as a backup? Supposedly they have generators/redundancy but the place requires so much power that that can only maintain critical functions (I guess ensuring incoming flights can still land and taxi in the mins after the power loss).
One potential solution is to add a connection to a second substation. For example, Laleham is a few miles south of Heathrow, and can be fed without sharing any infrastructure with North Hyde.
I doubt it's worth the additional expenses, though. Transformers exploding like this is extremely rare, and the main reason this one has such an impact is because the firefighting effort required the other two transformers to be shut down. Investing in better physical separation between the individual transformers is probably a way more effective investment.
Grid power is hard. Even with local generation failovers for air and ground safety systems, Heathrow is massive and uses a lot of power (1-2MWh/day). It's hard to route around that sort of demand.
I don't disagree that this is something that shouldn't happen, but that's what we say for almost every preventable grid failure. I think this is a national inconvenience rather than a security issue though. There are short-term alternatives which will be used.
I know your joking, but some flights have been diverted to Paris where the airlines are bussing passengers to London! So yeah, there kinda is a replacement bus service for some flights!
> Perth Qantas customers who had their flights diverted from London to Paris after a massive power outage at Heathrow Airport will be put on buses to take them to take them to their final destination.
The substations decribed in the power network case study above are for local distribution – 33kV stepping down to 11kV (×2) and 11kV to 415V (x12).
The substation on fire (North Hyde) is a 275kV major distribution substation.
That's a fairly significant distribution loss in itself (not just Heathrow but also 16,000 homes), and rebalancing the distribution will need careful coordination – flipping the switch on a load the size of Heathrow would then imbalance the network for the new distribution supply site.
UK Power Networks are the local network operator for London and the South East. The substation that has gone boom is a National Grid one, so it's presumably affecting things upstream of local substations. I'm surprised there's a single point of failure at this level though, you'd think Heathrow would be considered important enough to have multiple feeds at a national grid level.
Literally just guessing: that substation is on the train route to central London, which is the main public transport connection in and out of Heathrow. Indeed the Elizabeth tube line is suspended on the Heathrow branch.
So perhaps the core issue isn't inability of the airport to operate, but of people to get in and out.
I think it's likely the Elizabeth Line branch is suspended because the stations are closed, and the stations are closed because there's no power to the buildings.
I doubt they would suspend flights for that. Heathrow is used by people from all over South England, not just London, so a good proportion of customers come by car. Not to mention the people doing transits. Also TFL has a stock of buses which they use if a rail line goes down.
What I don't get is that the government now says it wants a 3rd runway (this has been debated for 30 years). Why add a 3rd runway, costing billions and taking decades, to an airport that can't use it 24-7 due to noise restrictions, and doesn't even have resilient power from the grid. Heathrow should have been bulldozed years ago and replaced with housing, and the estuary airport built. Or the Maplin Sands project 50 years before that.
Adding a runway to an existing airport is relatively low risk and comparatively cheaper than building a new major airport altogether. Anyone considering the latter will surely look at the Berlin Brandenburg Airport [0], which ran roughly €4 billion over budget and opened nine years behind schedule. Given the dire financial situation of the United Kingdom right now, I would wager this is an incredibly hard sell.
I feel like if you build that extra capacity it will immediately get used and you will still have no extra capacity in these situations. An airport holding extra capacity feels like it's just burning money given the demand.
Old oil transformer. The insulation breaks down in old transformers. It happens sometimes. No need to involve Russian conspiracy theories at this point in time... :-)
You joke but make a good point, most major installations have backup diesel powered generators to provide power for a certain limited but generous time.
What happened with Heathrows generators? Did they kick in? Do they have any?
Readit News
> The power vulnerability for airports was never made more obvious and painful than in Atlanta seven years ago. An underground electrical system fire in late 2017 damaged two substations and caused a complete outage lasting nearly 12 hours at Hartsfield-Jackson International Airport
https://www.microgridknowledge.com/microgrids/article/551275...
1. UK’s has one major airport to get out of the country—Heathrow. Gatwick and that lot don’t carry the same weight. When Heathrow goes down, you’re proper stuck. Atlanta has DC, Miami right there.
2. UK allows transit visas, so half the people transiting can’t even step out the terminal, what do they do when the airport is closed?
The US doesn’t allow that, everyone clears customs/passport control, so no ‘no man’s land’ limbo for stranded passengers.
3. Heathrow's outage is going to take 24 hours as of right now. That's twice Atlanta
Both Gatwick [0] and Stansted are busier than either Washington airport [1], and if you're considering Miami as an alternative to Atlanta then why not similarly ridiculous options like Paris, Amsterdam, Dublin for passengers stuck in Heathrow?
Miami and DC aren't even close to the nearest major airport cities to Atlanta. Charlotte and Orlando are many hours closer and busier [1] in terms of commercial passengers (though still not as convenient as the UK's comparable airports).
Only about a quarter of Heathrow passengers are transiting [2] and a significant portion of those are citizens of the US, EU, UK and other countries who don't need a visa. Maybe 10% of passengers are stuck in limbo, not half of them.
[0] https://en.m.wikipedia.org/wiki/List_of_busiest_airports_in_...
[1] https://en.m.wikipedia.org/wiki/List_of_the_busiest_airports...
[2] https://www.statista.com/statistics/303939/flight-transfers-...
"right there"
It is a ten hour drive from Atlanta to DC. It is a nine hour drive from Atlanta to Miami.
It is a six hour drive from Heathrow to Paris.
2: I don't know if they've done it, but the UK can grant entry for a few days to affected passengers. This will be part of a contingency plan.
3: The airport reopened for some flights already.
I’ve been using Edinburgh airport and Glasgow airport for 40 years to “get out of the country”.
Airside to airside bus shuttle?
> The US doesn’t allow that, everyone clears customs/passport control, so no ‘no man’s land’ limbo for stranded passengers.
Anchorage International Airport, amongst few (less than a handful really) other US airports, have separate international section with sterilised transit.
To be fair, I'd probably be more interested to hear what major airports are doing to avoid a reoccurance of CrowdStrike-type scenarios. Which is perhaps a more likely re-occurence than loss of substation feeds.
Military airports are working fine. National security doesn't rely on civilian airports. And communications networks aren't disrupted or anything. This isn't enabling terrorism.
It's absolutely a huge economic issue. Economic-political. But I'm not seeing a national security angle here.
https://en.wikipedia.org/wiki/National_security
Large-scale issues that impact the economy are typically under the "national security" umbrella. It's a term that uses the broad definition of "security".
Whether this incident qualifies, I don't know, but "national security" is definitely not just about military stuff. Just like how "food security" isn't about physically protecting food from damage.
https://en.m.wikipedia.org/wiki/National_security
The Russian war of aggression on Ukraine is a prime example: power infrastructure, transportation, communications, commercial hubs, healthcare, and general civilian targets of opportunity are all targeted with high frequency by Russian forces.
UK national security interests are spelled out in summary beginning on page 5 of this PDF, "Government Functional Standard: GovS 007: Security", notably
Each organisation’s governance and management framework shall cover physical, personnel, cyber, incident management, technical and industry security
<https://assets.publishing.service.gov.uk/media/613a195bd3bf7...> (PDF)
The US electric grid has also been of significant concern. Ted Koppel's book Lights Out (2015) addressed this specificly:
<https://news.wttw.com/2015/11/09/ted-koppel-americas-vulnera...>
As an example of non-military focus, the present US national security policy leads with ... tourist visas:
To protect Americans, the United States must be vigilant during the visa-issuance process to ensure that those aliens approved for admission into the United States do not intend to harm Americans or our national interests.
<https://www.whitehouse.gov/presidential-actions/2025/01/prot...> (20 Jan 2025)
An earlier document from the Bush II White House leads with:
People everywhere want to be able to speak freely; choose who will govern them; worship as they please; educate their children—male and female; own property; and enjoy the benefits of their labor.
<https://georgewbush-whitehouse.archives.gov/nsc/nssall.html> (2002)
Wikipedia's National Security article notes:
Originally conceived as protection against military attack, national security is widely understood to include also non-military dimensions, such as the security from terrorism, minimization of crime, economic security, energy security, environmental security, food security, and cyber-security.
<https://en.wikipedia.org/wiki/National_security>
Economic and infrastructural sabotage isn't an unprecedented act in the last few years anyhow.
Deleted Comment
And no, it is not a national security issue. There are three other airports in the London region, plus RAF Norholt and RAF Kenly inside the M25 ring.
I don't imagine an american being so dismissive about JFK being taken offline.
So basically this is what Putin is trying to do - find vulnerable points and attack them. For now, creating disruption without human casualties.
No. Its not.
Its the fact that the decades of under-investment in power distribution infrastructure is coming home to roost.
Its no secret there's little to no "fat" in the UK grid system. Hence it has difficulty coping with black-swan events such as this.
Anyone who buys datacentre space in London knows the reason prices have gone through the roof in recent years. Its becasue the grid simply cannot get the extra capacity to where it is needed. And this is before energy prices started rising due to the UK's electricity being mostly dependent on gas (previous governments having sold off gas-storage facilities to build houses on the land instead).
That's why its also a pain in the backside to build new banks of EV fast chargers anywhere in the UK. Getting the power there involves long, protracted, discussions with the grid followed by payments of large amounts of money and a written promise to the grid that you agree to load-shedding at any time if necessary.
I suspect you will find its not a single point of failure either. Its just that Hayes is a high-demand area, so see above for lack of excess capacity .... if one site goes boom, the other will struggle to take on 100% load.
Hayes (North Hyde) is a few miles NE of Heathrow, but Laleham (similar sized) is only a few miles South - I’d would have assumed both served as fully redundant supplies for the airport, given it’s critical national infrastructure.
(The old BBC Television Centre in London had three independent supplies, I believe)
Wind was the dominant source of energy in the UK last year:
https://reports.electricinsights.co.uk/q4-2024/wind-becomes-...
The expense is unpleasant, but the money has to come from somewhere, and the user paying is easier to justify than all the other bill-payers collectively or the taxpayer.
My second thought is, UK infra is crumbling so bad, this is really most likely just business as usual...
"Heathrow Doesn't Know When Power Will Be Back, Days of Disruption Expected" - https://www.newsweek.com/heathrow-airport-fire-counterterror...
If the entire transformer is lost, procuring replacement transformers for substations can take from several months to years. Insulation failures are relatively common in older power substations. It seems someone should have done a better job preparing disaster recovery scenarios for Heathrow.
Edit:
BBC reporting "some power" restored on a "interim basis" as the power company is now using a different substation. It would be curious if the increased effort on other substations would then cause further power failures...A bit like the postmortems of global cloud providers, where taking a node out, causes increased stress on other nodes...
(edit: and are back)
https://www.thelocal.dk/20250321/sas-cancels-flights-from-no...
https://www.bbc.co.uk/news/articles/cly6e24q8glo
"Power outage cancels, diverts flights at Kennedy Airport" - https://apnews.com/article/new-york-city-power-outages-eb883...
https://www.gao.gov/assets/gao-23-105203.pdf
I doubt it's worth the additional expenses, though. Transformers exploding like this is extremely rare, and the main reason this one has such an impact is because the firefighting effort required the other two transformers to be shut down. Investing in better physical separation between the individual transformers is probably a way more effective investment.
Grid power is hard. Even with local generation failovers for air and ground safety systems, Heathrow is massive and uses a lot of power (1-2MWh/day). It's hard to route around that sort of demand.
I don't disagree that this is something that shouldn't happen, but that's what we say for almost every preventable grid failure. I think this is a national inconvenience rather than a security issue though. There are short-term alternatives which will be used.
It's 3 orders of magnitude more: 1-2GWh/day.
https://www.heathrow.com/content/dam/heathrow/web/common/doc...
That number doesn't seem that high, compared to a single high-speed train running at about 300kph or above. Or lets say all of the London Tube/DLR.
Seems like nothing, actually.
Dead Comment
> https://thewest.com.au/travel/perth-to-london-flight-diverte...
> Perth Qantas customers who had their flights diverted from London to Paris after a massive power outage at Heathrow Airport will be put on buses to take them to take them to their final destination.
https://www.bbc.com/news/live/cly24zvvwxlt
Sounds weird that one substation going down would close everything.
The substation on fire (North Hyde) is a 275kV major distribution substation.
That's a fairly significant distribution loss in itself (not just Heathrow but also 16,000 homes), and rebalancing the distribution will need careful coordination – flipping the switch on a load the size of Heathrow would then imbalance the network for the new distribution supply site.
You are off by a large number. More like 62,000 customers affected (although "only" 4,800 are actually without power right now)[1].
Also that area is more than just "homes". There is a lot of heavy elecrical load commercial stuff going on in that area too.
[1]https://powertrack.ssen.co.uk/powertrack#QQ0573
So perhaps the core issue isn't inability of the airport to operate, but of people to get in and out.
[0] https://en.wikipedia.org/wiki/Berlin_Brandenburg_Airport
But what can the UK do about the likelihood of Floods?
The bird migration that constantly fly where the Estuary would be
Or an accident happening at the Grain LNG Natural Gas Storage plant, one of the largest in the world that’s right next to where the airport would be?
https://en.wikipedia.org/wiki/SS_Richard_Montgomery#/media/F...
"How to Prevent Substation Fires": https://www.oilbarriers.com/blog/suppress-substation-fires/
https://youtu.be/2np745xyQ7o
What happened with Heathrows generators? Did they kick in? Do they have any?
Edits: yes they did kick in as normal https://www.standard.co.uk/news/uk/heathrow-ed-miliband-nati...
Note that usually backup generators are only for essentials like air traffic control, landing lights, and operating emergency stuff.