tcas question

[406pilot]

hi,

this happened to us yesterday beautifull night flight and we saw traffic coming towards us appeared to be below,i was the pf at that time and the captain confirmed with atc that there was indeed a traffic coming inbound from the opposite direction..so we crosses safely...but here is the big mystery the traffic was 2000' below us and tcas never painted anything at all
no TA or RA the screen was as if there was no traffic..we tried to play around with the range and above below switch but nothing...on landing we did a tcas test and the system showed ok...has this happened to anyone else..will give details of the specific tcas system installed..

keep it up there fellows,

no more 406pilot.

ps:to all the wise guys out there the opposite traffic was a reputable airline and we were both given squak codes so i dont think his txdr was off

[ROSCO328]

This may sound like a stupid question but what range scale did you have selected? On the Dornier 328 tcas info is only displayed upto a max of 25nm after that tcas is obviously still on but traffic indications are removed from the display to avoid clutter. Just a thought.

[406pilot]

hi rosco,

there are no stupid questions in aviation my friend..to answer your question the max range on the tcas is 25 nm and we had it on there ...and nothing...we even tried cycling the range selector but no joy there either...i am off flying tomorrow same plane in a busier airspace so i hope things are better there.....

keep it up there fellows,

no more 406pilot

[406pilot]

hi ASFKAP....

thanks for the info, wow your're great help buddy..i just got back from jo'burg where there is lots of traffic always, the atc was vectoring around traffic that we never saw on the tcas but saw visually,eventually we knew the unit was upto no good, its not a nice scene....as we noted it down several times on the tech log the engineers just counter signs it and writes "sytem tests satisfactorily in the ground"
if possible can you send me an email detailing what exactly is the problem or wht processors needs to be changed so that i can show it to our brain dead engineers...

thanks for your help...

keep it up there fellows,

no more 406pilot(b737-200)

[Piltdown Man]

I recognise this one. Just after a box upgraded our on TCAS system, we had a few systems that refused to show "Other" and "Proximate" traffic. Problem was eliminated with a software upgrade. Engineers, in their normal way, said that it would work fine in the event of a TA or RA. But we never got close enough to threat traffic to test that theory, apparently...

[Capt Pit Bull]

Might have been interference limiting mode.

Was there much other traffic around? (mental picture, not Traffic Display)

CPB