The prime minister has said he is “deeply concerned” about the closure of Heathrow Airport as a result of a power cut caused by a fire at a nearby electrical substation.
Sir Keir Starmer told the BBC “there are questions” for bosses of the UK’s largest airport to answer over the the 18-hour long closure on Friday, which disrupted the journeys of some 200,000 passengers.
On Monday, Heathrow defended its decision to shut down following claims that it did have enough power to operate after the substation fire.
The airport said it had to ground flights due to the time it took to switch from the damaged substation to two alternative power supplies, but added “lessons can and will be learned”.
The impact of Friday’s fire from a single power source has raised questions over Heathrow’s resilience and disaster plans, which sees thousands of passengers and millions of pounds worth of trade pass through its four terminals on a daily basis.
The airport, along with National Grid, which oversees the UK’s electricity network, and Heathrow, agreed the impact of fire which broke out at the substation in Hayes was unprecedented.
But John Pettigrew, chief executive of National Grid, told the Financial Times that two other substations remained operational and capable of powering the airport.
He said he could not recall a transformer failing to such an extent in his 30-year career, but said there was a “level of resilience” provided by two other substations.
“Each substation individually can provide enough power to Heathrow,” he said.
In an interview with the BBC, Sir Keir said there were still unanswered questions.
“I don’t want to see an airport as important as Heathrow going down in the way it did on Friday, so I’m not comfortable with that for one second,” he added.
An investigation has been ordered by the government to establish what happened, with initial findings to be provided within six weeks.
An internal review of the airport’s crisis management plans and its response will also be undertaken by former transport secretary Ruth Kelly, who is an independent member of Heathrow’s board.
Transport Secretary Heidi Alexander told the BBC the airport’s “well designed” resilience plans had worked as intended, but added they were never designed to protect the entire energy supply for the whole airport.
Asked if she had confidence in Heathrow’s leadership team after reports some senior management went back to bed, leaving the decision to close the airport to more junior executives, Alexander said it was “not a matter for me”.
She said she understood Heathrow’s chief operating officer, Javier Echave, was “taking some of the critical decisions” early on Friday, but that she got a “pretty much instantaneous response” when she requested to speak to the chief executive Thomas Woldbye.
“The individuals who need to ask themselves whether they have full confidence in Heathrow management are the Heathrow board,” the Transport Secretary added.
The BBC has contacted the airport regarding the reports.
Heathrow has emergency back-up power supplies, which use diesel generators and batteries, but these only keep crucial safety systems running, such as landing equipment and runway lights.
A separate biomass power generator also provides heat and electricity to Terminal Two.
The airport’s chief executive, Mr Woldbye, has said a back-up transformer failed during the power cut, meaning systems had to be shut down before power could be restored.
Heathrow managers decided to close the airport on safety grounds while they switched to the alternative National Grid supplies.
“Given Heathrow’s size and operational complexity, safely restarting operations after a disruption of this magnitude was a significant challenge,” a spokesperson said on Monday.
“Our objective was to reopen as soon as safely and practically possible after the fire.”
The length of the shutdown infuriated airlines, which had to pay for the cost of refunding and rebooking customers as well as putting stranded passengers up in hotels and covering food expenses.
Willie Walsh, the former British Airways boss and head of the airline organisation IATA said on Friday it was a “clear planning failure by the airport”.
The BBC has since contacted the major airlines operating out of Heathrow’s terminals to ask how much Friday’s closure cost, but all approached have declined to comment or not responded.
It is understood there are concerns within the industry however that there is no mechanism of recouping such costs from the airport responsible, when disruption to flights is out of the control of airlines.
