Amlb

Just noticed the Faro flight is doing loops east of Brest at 10,000ft???

PETER01

If I may add for those maybe not aware it is Squawking 7700 which is an emergency squawk (code) and AIUI can be for various reasons.

I see @Waterhorse is online just now so perhaps we get a post from him or Heathrow Tower or atcodave

DYKWIA

Looks to be heading back to LHR. Was at 34k feet, so I assume some sort of pressurisation issue?

Waterhorse

Only to say I have no more info than you. As PETER01 says 7700 is the Emergency squawk - it can everything from minor issues to a full on disaster. ATC Radar is now all pretty much processed digital imaging so the use of the code allows ATC a clearer view of things and let’s everyone around know there is a degree of urgency required in the handling of the aircraft

PETER01

Thanks Waterhorse.

Are most 7700 squawks downgraded in the air? (If that's the right phrase?) or I suppose each 7700 squawk varies in separate degrees of 'emergency'

Amlb

And now heading back to LHR

jacksprat

She’s squarking 2044 now, so clearly happy enough to return to LHR without priority treatment.

Waterhorse

Probably, I don’t have the stats on that but I would say that most urgency situations get downgraded after we have been working the problem for a while. Initially we get as much help as we can until we have assessed the situation and how bad it is after some drills have been run. ATC sometimes leave us with the squawk as it lets others know we are getting special handling.

Mekko

She's down safely and has vacated 27R, so presumably no need for emergency services.

danielflyer

Which website do you use to see the squawk codes? I've never seen this on Flightaware.

Mekko

I find https://globe.adsbexchange.com/ best; you can customize the data shown in the table to include squawk.

AC681

FlightRadar24 will notify you if there's someone squawking any of the emergency codes

Oxon Flyer

As per OP, todays BA508 16:05 LHR-FAO G-EUUC returned to LHR turning back over northern France.

Todays BA594 13:15 LHR-FAO G-EUUT also returned to LHR, turning back at pretty much the same place.

Any insights into what happened here ?

Amlb

As above!

also Plane finder

Heathrow Tower

Just for background info, As Waterhorse alluded to here:

Once outside the immediate vicinity of an airport, the airspace is divided up into sectors, each with having its own controller looking after it. In busy and complex airspace, these can be quite small, and have both lateral and vertical boundaries.

If you imagine a controller working a sector that is maybe 60nm x 60nm, and from 8000ft to 19000ft (LOW), and on top of that is another on from 19000ft to 30000ft (MIDDLE), and another one on top of that from 30000ft upwards (UPPER) (this one will be bigger laterally as it will be less complex). LOW controller only cares about traffic in her/his sector, plus those climbing up into it from underneath and descending down into it from above, but they don't care about flights staying in the UPPER sector. They wil have a height filter set on their radar, lets say at 3000ft to 15000ft, anything below this will only show up as a small blip. Anything inside that altitude band will have the full label (callsign, altitude, destination/route code, speed, etc). Likewise for MIDDLE sector, they might have the height filter set at 13000ft to 23000ft. and so on.

If an aircraft in the UPPER had an emergency, and put on an emergency squawk (either because the flight crew did it, or was instructed to do so by ATC), any emergency squawk will cut through any height filter, so all the surrounding controllers will know who has just had an emergency declared on their frequency. This helps in many ways.....they can start supporting them by holding on to traffic they were about to transfer to them, they know not to call them on the landline to coordinate, they themselves might start informing other agencies/sectors of the emergency as a heads up. The breaking through the height filter is esepcially useful if it's a rapid decompression which will enable in this case the MIDDLE and LOW sector controllers to move their traffic out from underneath the rapidly descending aircraft.