Mode S radar identification
 

In the UK, MATS Part 1 Section 1: Chapter 6: 5B appears to allow

"direct recognition of the [Mode S] Aircraft Identification Feature on the situation display [to] be used to establish surveillance identification, subject to either:
(1) correlation of the Aircraft Identification Feature with the aircraft identification entered in the flight plan and displayed to controllers on flight progress strips; or
(2) correlation of the Aircraft Identification Feature with the aircraft’s callsign used in a directed RTF transmission to the controller."

I had Southend do precisely that the other day:

"Southend, G-XXXX request traffic service"
"G-XXXX, Southend, identified, traffic service, pass your message"

However on departing Cambridge and changing to Stansted/Essex, I'm still asked to squawk ident.

I'm curious to know why "direct recognition" is not used by TC in those circumstances, and also whether Mode S alone is used for radar identification in this way in other states.

I'm taking a guess here but I imagine it's because TC is a lot busier than Southend and looks after a larger area. Asking you to squawk ident speeds up locating you in their scan.

I'm not sure that Swanwick (where Essex/Stansted etc are located) has Mode S identification capability. Area control certainly doesn't have it so one of the old methods will have to be used.

Judging by the number of incorrect ACIDs that can be seen on outbound aircraft, that only get corrected when they pass the FIR boundary, you could well be right.

I believe it's just an attention getter as they are working on a large scale. Bit like overlaid DF on a terminal screen it just drags your eyes to the right part of the screen...

The "callsign" information attached to the radar return displayed on our screens in TC is not Mode-S derived. It is simply the flight-planned callsign converted from the squawk the aircraft has selected (relies on correct selection of squawk from the crew). To access the Mode-S I/D we need to manually select each radar return, which then displays the Mode-S info in a separate section of our screen. We are busy controllers, so to save manually selecting (wrestling with a roller-ball!) each aircraft we want to identify, we instead just use the more traditional method of "squawk ident".
I could also mention that most of the crusties probably don't even realise we can identify using mode-S, but I wont...

@twentypoint4, same as "old" system at PC, ITEC uses Mode S
This retired crusty used Mode S often, especially on the quieter West Coast sector when you get to know the regular customers who select 7000 but often monitor the frequency only, calling them to find their intentions made UK FIS services to other customers a lot easier.
Also, nice to see the Mode S greetings from a few Loganair crews at XMAS and NY !

<<Bit like overlaid DF on a terminal screen >>

I thought that went out many years ago?

We had it at Farnborough when we operated from the Mk3 control tower with Plessey Watchman consoles until late 2002, then we moved to the Mk 4 tower and switched to TFT screens and lost the facility.
It's called 'progress'. I believe Farnborugh 'ditched' DF completely about 3 years ago.

OK T. I think it went from Heathrow 25+ years ago. It was much missed by the SVFR man!

My unit still has it, saves a whole lot of "Squawk Ident" on the R/t:ok:

Not all units have the luxury of mode S; it certainly makes ATS provision a lot easier and you get a real feel for how your area operates as you get familiar with call-signs and routes (7k aircraft). The downside is, mode S equipped aircraft are indicated with a small dash next to the label box, and the amount of 7K squawks I see with no altitude (i.e. equipped but not selected on) is staggering. But then again . . . . . .

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