ATC opinion please

[Eau de Boeing]

Hi

Just a quick question from something that came up during one of our technical training days and I guess it is probable aimed more at the area controllers than terminal ones.

If we suffer a rapid decompression and have to initiate an emergency descent, is the preference nowadays for us to set 7700 as well as making a Mayday call or if we are identified and receiving a service to maintain our original squawk?

Cheers

[hangten]

I'm not an area controller but I am 99.9% sure the preference is to set 7700. I believe on all modern displays/radar processors this highlights your aircraft and maintains the callsign.

Prepare for higher authority...

[Vercingetorix]

Preferably both (if you have the time). It gets the adrenaline running all round the units, also 'cos of transfer to another sector/unit it initiates the back up to help you out.

[5milesbaby]

I am a UK area controller and I personally would prefer you to select 7700 but if you are looking for that in writing in a document then I'm not sure it is! Selecting 7700 puts a flashing red and yellow box around the datablock but the information is still the same. If you make a Mayday call stating emergency descent, the natural response will be "squawk 7700" in nearly every case.

[The Many Tentacles]

From the UK area side, it also cuts through any height filters controllers might have selected on the radar so coordination can be effected a lot quicker should it be required

[Talkdownman]

is the preference nowadays for us to set 7700 as well as making a Mayday call or if we are identified and receiving a service to maintain our original squawk?
Talk Mayday = Squawk Mayday. No question. Don't faff about.

Flashes
Forces through
Retains data block at some ACCs
Attracts attention and support
In your interest too...

[In_Transit]

As long as it's safe for you guys to do so in the cockpit, definitely do both! Squawking 7700 is a lot quicker for us to see and start getting other traffic out of your way.

[rab-k]

As a non-SSR bod, 'ADS Emergency' please, ASAP...:ok:

[055166k]

The best guidance [UK] can be found in United Kingdom Aeronautical Information Circular P138/2012 "Emergency Descents in UK Controlled Airspace"
The P stands for pink...because it is safety related. The AIC will explain slight UK differences from ICAO and is worth a read; it also gives an explanation to some other questions.
I prefer the AIC guidance rather than the more sterile interpretation given in the UK AIP En Route section.... ENR 1.6 SSR Operating Procedures..... page ENR 1.6-3 para 2.2.1[a].
Sorry I can't do the cut and paste thing........but if you really want to know you will find it. rgds

[055166k]

Sorry...should have said...NATS | AIS (http://www.ais.org.uk)

[PT6A]

Setting 7700 also makes sure you are front page news! Thanks to the likes of flightradar24 etc!

[blissbak]

You sould do whatever your SOP tell you, as far as I know it was a checklist item.