*

Travel consultant estimates cost of closure at $26 million

a day

*

Airport handles around 1,300 flights a day

*

Minister says government is looking at infrastructure

lessons

*

Airlines chief blasts Heathrow over contingency planning

(Adds OAG data, quotes from academic, context, annual usage)

By Joanna Plucinska, Tim Hepher and Muvija M

LONDON, March 21 (Reuters) - The closure of Britain's

Heathrow is set to affect the global aviation system for days

and cost tens of millions of dollars, experts say, raising

questions over why better contingency planning was not in place

at the world's fifth-largest airport.

Experts were in shock at the scale of disruption - the

largest since the Icelandic ash cloud of 2010 - as they tried to

estimate the cost and breadth of the repercussions caused by a

fire at a nearby electrical substation that knocked out the

airport's power supply and its back-up power.

"It is a clear planning failure by the airport," said Willie

Walsh, head of global airlines body IATA, who, as former head of

British Airways, has for years been a fierce critic of the

crowded hub.

Heathrow is the busiest airport in Europe in terms of

the number of passengers flying in and out each day, according

to data firm OAG. All of Friday's 1,332 scheduled flights were

cancelled.

The blaze, which was reported just after 2300 GMT on

Thursday, forced planes to divert to airports across Britain and

Europe, with many long-haul flights simply returning back to

their point of departure.

The shutdown comes less than a year after Heathrow told

Britain's Civil Aviation Authority in a filing that it was "a

leader in airfield resilience".

But several experts pointed to potential weakness in its

back-up plans.

Travel consultant Paul Charles said Heathrow's closure

could cost the aviation sector around 20 million pounds ($26

million) a day, with no guarantee the airport would reopen on

Saturday.

"Heathrow is such a vital piece of the UK's infrastructure

that it should have fail-safe systems," he added.

Tony Cox, an international risk management consultant, said:

"I can't remember a piece of critical infrastructure being

wholly shut down for at least a day because of a fire. I can't

think of anything comparable."

The chaos also exposed the potential vulnerability of

critical infrastructure at a time when security has risen to the

top of the European agenda.

British police said counter-terrorism officers were

investigating, but there was no initial indication of foul play

in the substation blaze.

Energy Minister Ed Miliband said the fire had disabled

back-up power and that engineers were working to deploy a third

source.

Like most large airports, Heathrow has what's called an

operational resilience plan, which sets out to identify risks

that could upset operations. It was not immediately clear,

however, whether back-up power had been singled out as a

potential vulnerability.

In 2023, Heathrow completed a new energy strategy,

pledging more renewable energy "whilst protecting the

resilience of our energy network," according to its latest

annual report.

Heathrow and the CAA did not immediately respond to

requests for comments on contingency planning.

CLEARING THE BACKLOG

The closure is set to have days-long knock-on effects

globally, leaving many passengers stranded as carriers

reconfigure their networks to move planes and crews around.

British Airways has warned in the past that Heathrow is so

overstretched that recovering from disruption can cause even

more chaos, as planes and staff must be properly repositioned

even as the facility runs at full capacity.

"There will be impact running on several days, because

once aircraft are grounded somewhere away from an operation,

they are stuck there with the crews operating the flights," said

aviation consultant and network planning expert John

Strickland.

Britain's airspace is among the busiest in Europe, and

technical outages have raised concern in the past.

An outage of Britain's air traffic control system NATS in

2023 cost over 100 million pounds, according to the CAA.

Tim Green, head of department for electrical and

electronic engineering at Imperial College, London, saw his

UK-bound flight forced to turn back to North Carolina on Friday.

Speaking to Reuters, he described the complex arteries

feeding into Heathrow, which consumed 271,080 MWh of grid

electricity in 2023, according to its annual report.

"There's a lot going on at an airport," he said.

Heathrow must supply power to shops, restaurants, public

spaces and emergency lighting, he said, while a separate

category of electricity supply feeds safety systems like radars,

navigation equipment and landing lights.

"Some of that will, of course, be backed up by emergency

generators. But I think the airport would rather shut down some

of its operations than accept more aircraft when it's in a

compromised state like that," Green said.

($1 = 0.7730 pounds)