Question for UK ATCOs (from a pilot...)

[anson harris]

Hi guys,
I did a quick search but couldn't find anything on this... I understand there are certain things that you can see on your screens via Mode S, but was wondering about the info you get about routing.
I understand that if we are direct to, let's say, CPT, does that show up on your screen? If it does show up, is that data entered by the ATCO into your system, or does it originate from the aircraft?
I'm only wondering because we often select "abeam points" when given a direct routing, which enters a load of extra points into the FMC prior to the direct to WP, and it occurred to me that this might confuse your picture, if indeed that's where it comes from.
Thanks
Anson

[OhNoCB]

Standing by to be corrected, but as a pilot - not an ATCO I am not aware of any link between the FMC on our aircraft and enhanced mode s.

[anson harris]

Just the MCP right?

[dagowly]

Routing comes from your flight plan, the only thing mode S would show for your aircraft is the selected heading and level (if you have autopilot). for example at swanwick it would go onto the system and we'd be able to see your way points. VFR flight plans, usually not unless you're speaking to us and we've paired your flight strip in the system up with the aircraft.

[Juggler25]

There is no link via Mode S that allows controllers to see the routing entered in the FMC (at Swanwick AC anyway). Our system tells us what route it's expecting you to be on and when we route you to a point we input that into the machine manually. If you are logged on to CPDLC we can send that routing to you electronically but not receive it.

[anson harris]

Ok thanks - that's exactly what I was after.

[DaveReidUK]

Early on in the development of ADS-B, provision was made for the aircraft to broadcast its next and next but one Trajectory Change Point (TCP and TCP+1).

I don't know if it's still in the spec, nor whether it was ever implemented, but this may be what the OP is referring to.

[Una Due Tfc]

Selected heading, selected FL and selected speed in some centers.

[PSR]

We see selected level, actual ias (not selected ias) and actual heading (not selected heading)

[JeroenC]

From mode-S?

[Talkdownman]

How else...?

[EastofKoksy]

JeroenC

From enhanced Mode-S. Now used by most European ATC. Don't know about other areas.

[Emma Royds]

I think you might be referring to FMC WPR (FMC Waypoint Reporting) which will send a position report based on FMC data to ATC. Should you select abeam points in your FMC with a 'direct to' clearance, then these abeam waypoints will be transmitted to ATC as part of the position report.

This really only applies to more remote areas such as the North Atlantic and not the UK. This is one reason why ETOPS Equal Time Points should not be entered into the FMC flight plan as it will confuse ATC.

[JeroenC]

Tnx, i always thought it was selected IAS.

[The Many Tentacles]

Tnx, i always thought it was selected IAS.

Nope, it's what you're flying so we can tell if you're being a bit naughty and not doing what we've told you to :=

[anson harris]

Nope, it's what you're flying so we can tell if you're being a bit naughty and not doing what we've told you to


Moi? No.....