Tcas Ra

[EightsOnPylons]

Dear forum,

I experienced a TCAS RA about 4 weeks ago and my buddy had one about 2 months ago. How common are TCAS RAs in Europe? Please tell me your experience with TCAS RAs. How long you have been flying and where and if you encountered.. Is there some website where you can read reports and also get statistics? I would be very interested to see this and read the reports..

thank you,
eightsonpylons

[HEATHROW DIRECTOR]

<<From personal experience, very few. Never heard another aircraft on frequency in Europe declare a TCAS RA.>>

I'm surprised at that, Mike. I've certainly seen a fair number in the London TMA whilst working as a Heathrow radar controller - the majority neither the fault of ATC nor the crews. Whether TCAS has been sufficiently modded to reduce them I don't know, but they tended to occur with traffic descending fast into holding patterns, or climbing fast under already level traffic. It's quite scary when you have a holding pattern full and someone says "TCAS RA; we're climbing"!

[HEATHROW DIRECTOR]

Thanks Mike.. guess the laundry bills are lower now!

[nitefiter]

I had a TCAS RA a couple of weeks ago whilst being vectored downwind for an ILS,( UK Regional Airport).Was caused we think by low level millitary traffic climbing with a high rate under us,equipment went ballistic and as we wernt visual we had to respond to it.

[FourTrails]

Nitefiter...

You say-

"Was caused we think by low level millitary traffic climbing with a high rate under us,equipment went ballistic and as we wernt visual we had to respond to it."

If you where visual, would you have ignored the RA????

Even if you think you saw it, how do you know that was the conflicting aircraft? There may just have been another...

[Xshongololo]

erroneous RA and TA callouts are less common with the new "version 7" Tcas software which specifically takes into account excess/large RoD or RoC caused by the traffic in question.
This software needs to be upgraded on all Tcas a/c....the exact dates i dont know.....hope this helps

[Diabolo]

Looking forward for the new ACAS Version 8 .

[juliet]

out of interest how are TA/RA's displayed on peoples displays. the ac i am on has a very large head down display showing range rings out to a max of 320 nm. TA/RA's are shown as a diamond or dot in varying coulours out to a max range of 40nm. means that when you get a TA or RA you can see exactly where the other ac is in relation to you making it easy to identify and, if good visual, ignore if you can see that there is in fact no conflict

[EightsOnPylons]

My understanding is that you ALWAYS have to respond to a TCAS RA regardless of beeing visual with the aircraft, correct?? I have been taught to always respond to it. If that is not common practice to do so it would create a significant danger since pilots aren't follwing the commands.

/eightsonpylons

[Krallu]

Hi!

I'm not a pro pilot yet, still on PPL lvl. But my feeling is that I would be nervous as a passenger if I heard that some pilots are starting to on their own analyse and ignore some TCAS warnings.

Well, some situations it might work but my experience is that humans aren't 100% correct, sooner or later someone will make a mistake and in the situation there are 2 aircrafts involved.

It feels much safer to always respond to the TCAS alert.

Just my toughts.

[nitefiter]

FourTrails
Sorry i didnt put it across very well in my earlier post,it was the TA that we were initially trying to verify, seemed unlikely given our position and altitude at the time and the elevation of the ground below us. (Initially nothing on ATC radar).As soon as it went to RA we still hadnt seen anything but of course had no further choice.

[juliet]

havent noticed much delay in the system that my ac has. a bit of common sense when using this system is not, i think, a bad thing. when there is ONE ac in the vicinity, it has been cleared to the level below me, and i can SEE that it will not hit me, i wont follow the RA as it is just getting upset about a high closure rate. this also goes for vfr situations where ac can get close to each other, though not dangerously so. my feeling is that in some situations the RA command can put you into a worse situation. need to bear in mind of course that you do know where all ac are around you due to their iff. people talk about the ac that you dont see, well you will see it on your screen, the only time you wouldnt being if the other ac's transponder isnt transmitting, meaning of course that there could be know TA/RA off it anyway as you need two valid systems. just think that common sense can be applied quite safely in many situations.

[FlightDetent]

Any chance PPRuNe audience know what are those two countries with AIP restrictions?


Furthermore on the subject of visual (mis)identification, TCAS is not constructed to give bearing information, and in my benign experience does a misarable job indeed.

cheers,
FD.

[PPRuNe Radar]

Diabolo

Looking forward for the new ACAS Version 8 .

You're going to have a long wait ... we're only on ACAS 2 at the moment !!!

ACAS 3 has been cancelled due to technical difficulties and ACAS 4 is still under development and will use other technologies (most likely ADS-B) to meet ICAO requirements for ACAS 3 (the provision of horizontal as well as vertical resolutions).


(Note that normally ACAS is written with Roman numerals, i.e ACAS I, II, III, or IV.)