Heathrow was warned a decade ago about relying on a single power station to fuel Europe's largest airport, it has emerged in the wake of yesterday's meltdown.
A 2014 report by infrastructure consultants Jacobs revealed that Heathrow could have been plunged into chaos by one "key weakness" - which came to fruition in the early hours of Friday at the North Hyde electrical substation.
Energy Secretary Ed Miliband has announced a wide-ranging probe into Britain's "energy resilience" as a whole following yesterday's chaos.
In the last decade the landmark London airport has been dependent on just three substations - and the report explicitly referenced how "potentially the entire airport" could be subjected to disruption by power outages.
"Beyond the management of supply and grid services, which lie outside the airport's control, the responsibility for managing electricity supply risk lies with the airport and businesses operating from the airport," the Jacobs report warned back in 2014.
Energy Secretary Ed Miliband has announced a wide-ranging probe into Britain's 'energy resilience' as a whole following the chaos
PA
"While some services can be temporarily supported with generator or battery backups, the key weakness is the main transmission line connections to the airport.
"Outages could cause disruption to passengers, baggage and aircraft handling functions and could require closure of areas of affected terminals and potentially the entire airport.
"Even a brief interruption to electricity supplies could have a long-lasting impact as systems can take time to recover."
As of Saturday afternoon, Heathrow is still battling to return to full operational capacity.
HEATHROW GRAPPLES WITH OUTAGE CHAOS - READ MORE:
'We are determined to properly understand what happened,' Ed Miliband said
REUTERS
And the airport's chief executive Thomas Woldbye said on Friday: "Heathrow uses as much energy as a city every single day.
"We don't have backup power for baggage systems, fuel systems, things like air bridges and so on.
"Whereas the safety systems are working, we can get aircraft in and out, most of the airport infrastructure comes to a standstill when we need to reset as we did yesterday."
Announcing an investigation into Britain's energy resilience, Miliband said: "The loss of power to the Heathrow area has caused major disruption to thousands of people and many businesses. We are determined to properly understand what happened and what lessons need to be learned.
PICTURED: Smoke rises from the North Hyde electrical substation
PA
"That is why, working with Ofgem, I have today commissioned the National Energy System Operator to carry out an investigation into this specific incident and to understand any wider lessons to be learned on energy resilience for critical national infrastructure, both now and in the future.
"The Government is determined to do everything it can to prevent a repeat of what happened at Heathrow. This review will be an important step in helping us to do so, as we deliver our Plan for Change."
His department said the watchdog's initial findings should arrive by early May.
Alongside the energy probe, the Metropolitan Police is investigating potential terrorist links to the fire - but "after initial assessment, we are not treating this incident as suspicious, although inquiries do remain ongoing," Commander Simon Messinger said.
