The ATC "party-line", a TCAS question.

[normally right blank]

Reading through the "ACAS II training guidelines for pilots" I came across an unknown expression to me:
"TA responses: .....c) “other available information is used to assist in visual acquisition. This includes ATC “party-line” information, traffic flow in use, etc."

What's the "party-line" (to follow? ;) )

[HEATHROW DIRECTOR]

Never heard of it - must be a recent innovation?

[Gonzo]

The 'Conga'?????????????:confused:

[brimstone]

"Party-Line Information" is information on the traffic situation obtained by pilots through overhearing communications between ATC and other aircraft. It increases aircrews' awareness and could be important during an ACAS encounter.

[Spitoon]

Let me guess. It must have been from a Eurocontrol document!

[normally right blank]

Thanks, brimstone. Makes sense now. Like the very first telephone we had. (Some) neighbours were well-informed!

Spitoon, Yes, from
http://www.eurocontrol.int/acas/ , ICAO Doc 8168, PANS-OPS, Volume I, Part VIII etc. etc. etc.

[Lock n' Load]

Just like Doris Day and Rock Hudson in Pillow Talk. Great movie. Would never have guessed he played for the other team.... :hmm:

[055166k]

This term will eventually become irrelevant.....the development of non-verbal ATC will remove a complete level of traffic awareness....but no-one has thought of that [or have they?]

[brimstone]

Actually 0551....this has been thought of. Some time ago the Massachusets Institute of Technology was asked by the FAA to carry out a survey amongst pilots concerning the importance to them of "party-line information". This was in recognition of the potential loss of such through increased use of Data-link communications between ATC and pilots.

Can't remember what the outcome was.

:confused: :confused:

[Llamapoo]

We also looked at it briefly in a broader study of datalink (at the ATMDC in Bournemouth). It was done for a Master's Thesis at Cranfield University.

The study wasn't concerned with the elimination of the party line, but it asked what the impact of losing it would be. I think without exception both pilots and controllers felt that it would be detrimental to safety. Our recommendation (echoed in the EOLIA project - European Pre-Operational Datalink Applications) was that only the 'housekeeping' comms be exclusively datalinked (i.e. no speech), leaving comms that contributed to situation awareness for all to hear.

[Spodman]

I have noticed on flight deck famil flights that it is relatively easy to keep a picture of what is going on in familiar sectors, I know where and when who calls, and can follow what is happening from the chatter. I also noticed the crew on each occasion were completely oblivious of this, and didn't even appear to be listening when their c/s wasn't mentioned.

A crew I flew into Adelaide with once were mystified by getting a speed reduction in the cruise. I pointed out the 4 aircraft that were transferred to our current frequency before us were probably in the sequence ahead of us, including the 747 that was track-shortened around us. They looked at the TCAS, saw nothing and said I was talking ****e, until I pointed out the 747 in our 2 o'clock!

The corollary is I'm completely adrift in a busy unfamiliar sector.

I suspect some of us on the ground greatly overestimate the usefullness or practicality of aircrew getting much of a picture from the 'party line'.

[Jerricho]

overestimate the usefullness or practicality of aircrew getting much of a picture from the 'party line'.

And perhaps the detriment of having a bi-lingual frequency, where not all is being "heard".