Heathrow closed all day Fri 21/3/25 - Aviation Impacts

[Jan Mayen]

I remember the days when you could fly from Gatwick to Heathrow, admittedly by helicopter.

 

[Deepgreen]

Neither could manage the aircraft (short runways) nor the passengers (no terminal facilities of remotely sufficient size).

IIRC there is a story on the aviation thread about a large aircarft that landed erroneously at Northolt instead of Heathrow, and it had to be stripped right down almost to the airframe to become light enough to take off again with minimum fuel on full power.

Farnborough can handle any aircraft, and does so during the air show, but of course these are empty and with minimal fuel. The runway is 8,000', so easily long enough for even an A380 to depart on an empty hop back to Heathrow if needed.

I remember the days when you could fly from Gatwick to Heathrow, admittedly by helicopter.

Also the 747 that plied back and forth - a coach!

 

[Bald Rick]

Farnborough can handle any aircraft, and does so during the air show, but of course these are empty and with minimal fuel. The runway is 8,000', so easily long enough for even an A380 to depart on an empty hop back to Heathrow if needed.

Not my area of expertise (as with most things!) but the landing area is only about 6000ft, would that be enough for a super heavy?

 

[Meerkat]

Farnborough can handle any aircraft, and does so during the air show, but of course these are empty and with minimal fuel. The runway is 8,000', so easily long enough for even an A380 to depart on an empty hop back to Heathrow if needed.

It isn’t 8,000 ft, more like 6,000ft. You cant use the whole length of the runway due to the hills at each end (it was longer in military days as they had different rules).
A landing A380 would need to be pretty light. I think the owners would be very unkeen as it would really upset the neighbours!

 

[Backroom_boy]

It isn’t 8,000 ft, more like 6,000ft. You cant use the whole length of the runway due to the hills at each end (it was longer in military days as they had different rules).
A landing A380 would need to be pretty light. I think the owners would be very unkeen as it would really upset the neighbours!

A380 taking off at the Farnborough airshow; however, unlikely to be fully laden.

 

[sharpener]

IIRC there is a story on the aviation thread about a large aircarft that landed erroneously at Northolt instead of Heathrow, and it had to be stripped right down almost to the airframe to become light enough to take off again with minimum fuel on full power.

There was another story that a gas works near Northolt had enormous letters N and O painted on the tops of the two gasholders to discourage exactly this kind of mistake.

 

[Tester]

N

There was another story that a gas works near Northolt had enormous letters N and O painted on the tops of the two gasholders to discourage exactly this kind of mistake.

Not a story, at South Harrow and well known to the locals.

Only one gasholder and NO on the side - search engines will easily find pictures.

Demolished 1987 and now a Waitrose.

I believe there was a similar gasholder approaching Heathrow, which is where the confusion arose - it acquired HR on the side (but not seen with my own eyes).

 

[Peter Mugridge]

I believe there was a similar gasholder approaching Heathrow, which is where the confusion arose - it acquired HR on the side (but not seen with my own eyes).

It was the tall grey corrugated style one next to the railway at Southall; it had the full LHR on it plus an arrow pointing in the right direction.

 

[CC 72100]

It was the tall grey corrugated style one next to the railway at Southall; it had the full LHR on it plus an arrow pointing in the right direction.

Yes, can confirm that. Was pointed out to me by the driver on a trip at the front out of Pad one afternoon 7-8 years back.

 

[nlogax]

The head of National Grid thinks Heathrow could have kept on operating through Friday via other substations. Evidently diversity of supply was there but a cold failover got in the way with all the inevitable lengthy airport systems checks that followed.

National Grid confirms Heathrow had 'enough power' after substation fire

Heathrow's boss previously said the shutdown was not for lack of power but to reboot complex systems.

www.bbc.com

The chief executive of the National Grid has confirmed power was available to keep Heathrow open throughout Friday's shutdown.
In an interview with the Financial Times, John Pettigrew said the fire that knocked out a substation was a "unique event", but that two other substations remained operational and capable of powering the airport in west London.

 

[m0ffy]

The head of National Grid thinks Heathrow could have kept on operating through Friday via other substations. Evidently diversity of supply was there but a cold failover got in the way with all the inevitable lengthy airport systems checks that followed.

National Grid confirms Heathrow had 'enough power' after substation fire

Heathrow's boss previously said the shutdown was not for lack of power but to reboot complex systems.

www.bbc.com

Makes sense, there is certainly a picture emerging of an insufficient customer network at Heathrow.

 

[stuving]

N

Not a story, at South Harrow and well known to the locals.

Only one gasholder and NO on the side - search engines will easily find pictures.

Demolished 1987 and now a Waitrose.

I believe there was a similar gasholder approaching Heathrow, which is where the confusion arose - it acquired HR on the side (but not seen with my own eyes).

Living close to the approach to Northolt at the time, I remember the story. It was 25th October 1960, and "only" a Pan Am 707. The pilot, Captain Warren Beall, was obviously very embarrassed but still did some press interviews about having to "brake pretty hard". He also referred to using the gasholder to line up for final approach.

But getting it light enough to take off was not that difficult, needing fuel only to get to Heathrow, which it did later that day. Mind you, they still shut Western Avenue at the time just in case. It even had passengers - well, Captain Beall was on board, and on arrival was immediately sent straight back to New York for an inquiry.

There was nearly a repeat with a Lufthansa 707 four years later. After that they painted NO on the landmark gasholder in South Harrow. We thought that meant "no" - but then we didn't know the one at Southall was marked LH, not YES (or SO). That LH became LHR later, I think because the three-letter code was then so much better known.

What's a bit odd is that confusing the two approaches can only happen for runway 25 at Northolt - which is the usual approach - and 23L at Heathrow. That was not usual even in 1960, and it was shorter than 27L or R - about 6000' I think.

 

[hwl]

Makes sense, there is certainly a picture emerging of an insufficient customer network at Heathrow.

Indeed - due to inadequacies would need a huge number of staff to manage fail over arrangement which they won't have had.

Like Thames Water decisions were taken long ago by different owners and management who have now departed.

 

[eoff]

Makes sense, there is certainly a picture emerging of an insufficient customer network at Heathrow.

They made a choice as to what the risk was and their plan was to reconfigure power within the airport (which they did) should one incoming supply fail.
I see that politicians are "deeply concerned", well they can bring back BAA and run the airport themselves.

 

[busesrusuk]

It was the tall grey corrugated style one next to the railway at Southall; it had the full LHR on it plus an arrow pointing in the right direction.

I think I captured the Southall gas holder (in the distance) in this general view taken from Queens Building:

LHR Terminal 1

A panoramic view of Terminal One at Heathrow in the early 1980's. Taken from the long since gone Queens Building.

www.flickr.com

 

[oldman]

They made a choice as to what the risk was and their plan was to reconfigure power within the airport (which they did) should one incoming supply fail.
I see that politicians are "deeply concerned", well they can bring back BAA and run the airport themselves.

Heathrow operates under licence from the Civil Aviation Authority, which gives government some say.

 

[thejuggler]

There may be a supply from other substations, but unless there is a system of complete UPS for the whole airport (and the hundreds of other properties which were affected!) which cuts in while the new substation supply is made live I'm not sure what there is to gain from the power company coming out with the statement there was an alternative.

One commentator who supposedly knows about this stuff says data centres have back up power and built in redundancy, They may do, but I'm not sure of many data centres the size of Heathrow.

 

[poffle]

It actually takes a lot of manpower and planning to carry out an orderly shutdown of lots of IT systems etc.

Recovering from a disorderly shutdown takes even more resources and lots of expertise.

One if the reasons why data centres put so much emphasis on redundant power supplies, redundant communications links, battery power and standby generators.

But data centres have commercial customers who can go elsewhere.

Heathrow is effectively a regulated monopoly. But I suspect it's a bit like the railways and DFT where the regulator decides in a great deal of detail what money can be spent on.

 

[Peter Mugridge]

I think I captured the Southall gas holder (in the distance) in this general view taken from Queens Building:

Yes, that is it.

 

[Airline Man]

I remember the days when you could fly from Gatwick to Heathrow, admittedly by helicopter.

I did that once, it was a Sikorsky S-61 and it took just fifteen minutes, G-LINK operated by BCal helicopters I believe.

 

[sharpener]

it was shorter than 27L or R

As a result of changing magnetic declination 27L is a comparatively recent name for it, IIRC in 1960 when I was a child it was 28R(!) and the reciprocal 10L.

 

[JN114]

As a result of changing magnetic declination 27L is a comparatively recent name for it, IIRC in 1960 when I was a child it was 28R(!) and the reciprocal 10L.

2nd of July 1987 for the magnetic deviation change of the Heathrow Runways.

 

[Nicholas Lewis]

The Transport Select Committee held a hearing today into the power failure and its consequences with the main players

Thomas Woldbye, Chief Executive at Heathrow Airport Ltd (HAL)​

Alice Delahunty, President, UK Electricity Transmission at National Grid (where the fire took place)​

Nigel Wicking Chief Executive at Heathrow Airline Operators' Committee Limited (looks after airlines interest)​

Eliane Algaard Operations Director at Scottish and Southern Electricity Networks (provides the power to the airport)​

https://committees.parliament.uk/event/22760/formal-meeting-oral-evidence-session/

Each representative gave an overview.

HAL CEO says as a result of the loss of Heathrow Nth S/Stn (fed from North Hyde substation at 66kV) they had lost all power to Terminal two, lighting in the approach road tunnel and their operations centre was affected. All aerodrome safety critical systems were maintained and that other terminals and facilities fed from the other two supply points remained operational.

National Grid stated that at North Hyde substation /stns two 275/66kV transformers were on line but one tripped off after the fire started so they reconfigured the site to a standby transformer but shortly after the remaining two transformers also tripped off (one was adjacent to the fire so not surprising given the ferocity of the fire but the other was some distance away but NG say wait for the NESO report for sequence of events and cause). They had one 275kV supply restored at 1000hrs once the fire was secured and a second supply available at 1600hrs.

Scottish & Southern Energy Networks (SSEN) were able to reconfigure there local network to restore domestic and business customers from 0400 onwards and importantly they were able to reconfigure their 66kV system at 0930 and give Heathrow a supply to their North substation at 1000.

Under questioning HAL are pointing the finger at NG/SSEN as its up to them to provide HAL with resilience. Basically HAL run the airport as three discrete load centres and interconnecting isn’t designed for the scenario that happened. The rep from Heathrow airline operators group claims that HAL waited till 0600 before they decided to reconfigure, SSEN confirmed to HAL they could have provided additional load from their two other s/stns. Also UK Power Networks run the internal HAL HV network and sounds like they needed to call people in.

Sounds to me HAL have too many systems that can’t cope with a loss of supply and be satisfied they will self restore so they are taking lowest risk approach and basically booting up every system from scratch and confirm they are working satisfactorily. In contrast railway signalling systems are expected to self restore under a loss of supply or where thats not acceptable be provided with UPS backup but seems outside of aerodrome safety systems (air traffic tower, landing lights and certain fire suppression assets) HALs protocol is to "cold start" all other assets like baggage handling, border control, escalators etc and check they are fully functioning before the output can be considered to be operational. HAL have instigate their own investigation being undertaken by Ruth Kelly former MP and chair of TSC although now a HAL board member so not much independence. CEO wasn't clear that full report could be issued due its security issues of the airport but let see.

What was interesting was several references made that Network Rail can cope with this sort of outage with remote switching and the way it runs its network.

 

[poffle]

I watched this hearing. It was noticeable that the senior managers from the two electricity companies were people who had been on site during the incident and could handle the details.

Heathrow was represented by the CEO who kept saying he wasn't an engineer and was very vague about what happened. The electricity network within Heathrow is managed by UK Power Networks who weren't present. I suspect that Heathrow's strategy is to batten down the hatches, kick up lots of FUD (fear, uncertainty & doubt) factors and hope the heat goes away.

 

[Bald Rick]

What was interesting was several references made that Network Rail can cope with this sort of outage with remote switching and the way it runs its network.

Presumably made by Eliane, who not so long ago was a Director of Asset Management at NR.

 

[poffle]

Presumably made by Eliane, who not so long ago was a Director of Asset Management at NR.

Alice rather than Eliane. NR would be connecting into National Grid and automatically switched to Didcot.