Notam says the stop bars for both runways are unserviceable.

It was more a general :uhoh: when something went “phutt”, fairly big time..I heard it was more than just guard lights/stopbars but even if it was just that given the quality of some of the readbacks you hear and the frequency of traffic crossing 09R to get to/from T4 I could perhaps understand ATCs reluctance to continue to operate at full flow rate if indeed that was the only issue.

Anyhow Inbound flights either held on the ground, some if not all of those already inbound to LHR were warned that they needed to prepare to divert, departures from LHR held.

I wonder what alternate procedures are there when stop bars non functional ? I presume stop bars are a significant safety system to prevent runway incursions, so when it is not serviceable, do they do things like increase traffic spacing etc ?

“They’re” should probably read “they were” since for example the OP posted 8 ish hours ago. Where I am some form of recovery plan has been in place for a while now and effected flights now en-route or have already arrived, albeit several hours late in a few cases.

The reason longhaul flights were held on the ground was that when this kicked off last night it was initially a case of “delay unknown” into LHR with no idea of when that delay might be updated, so I know some airlines initially made a decision to hold flights on the ground overseas rather than having them set sail towards LHR and then have to divert...

The days of sending an eager 'volunteer' to sit in a vehicle with a red/green Aldis lamp and a radio are long gone. "Switch doesn't work -> divert aircraft" is the modern approach.

If people were just asking about the technical side of what happened to the lighting last last night I'd agree you had a point, but they are not.

As we know this quickly became much more than an "ATC issue" so I'd hope others are allowed to contribute/"waffle" and try and answer questions asked by the travelling public in a "news" section about, for example, the reason for the OP's longhaul flight being held at IAD - that was a decision that wasn't made by ATC at LHR, it was made elsewhere.

I would assume that the LL/LHR ATCOs who routinely contribute to pprune will be aware the subject is being debated here and if they feel able to contribute I'm sure they will...

My best guess...

1. Early hours of the morning in London. Out of the blue LHR closed..completely, with no estimate as to when it might open again.
2. Multiple flights from multiple airlines already inbound to LHR from the likes of the Far East, the States/Africa/India planned to arrive in a few hours, just after the night curfew ends.
3. If LHR cannot open for arrivals after the night curfew then there will be mass diversions of those inbound flights with the preferred options close to London (Gatwick, Stansted, Luton, Cardiff etc ....getting full very quickly usually down to lack of parking spaces. Later arrivals are therefore at risk of diverting to far flung exotic alternates ....and then, if and when LHR opens, you’ve got dozens of aircraft out of position and crews potentially out of hours and unable to recover aircraft and passengers to London.

Given the above if you were in BA company operations at LHR when it all went wrong would you sit back and continue to allow those flights on the ground at outstations such as IAD to depart towards London on schedule and hope that LHR opens up in time for their arrival?.....Or would you ground hold those flights until you have some idea of if/when normal service of sorts will resume at LHR?