ACAS/TCAS Phraseology

[dv8]

What is the correct RT phraseology to use when you have an RA 'MONITOR (ADJUST) VERTICAL SPEED'?
CAP 413 and our company manuals only give examples in response to CLIMB/DECENT RA's

[flyboyike]

At my airline we just say: "(Center), (Flight), we had to deviate due to RA".

[Tarq57]

I don't think there is one. our MATS only provides examples for the situation where a TCAS climb or descent is commanded. Implies that (normally) you don't have to tell ATC. The exception would be if a controller had previously stated a min or max climb or descent rate, and TCAS countermanded that due to excessive closure. I would hope that would be highly unlikely; a controller would not normally ask for a vertical speed that would cause that situation. If it did happen, I'd suggest "### this is ###, unable to maintain xxxfpm due to TCAS" (while or immediately following the response to the prompt.)

Perhaps someone with more knowledge can provide the correct phrase, if applicable.

[FlapsOne]

There isn't one because it isn't really needed. You haven't deviated from the cleared flight path so no problem.

Common sense and airmanship would suggest you tell ATC about the alert at an approriate moment.

If ATC had given you fixed ROC (Swiss - God love 'em!) then, as markjoy suggests, something like "unable xxx due conflicting traffic" or similar will certainly do.

[dv8]

Thanks all for your reply's
Flaps 1 I agree with your point that you haven't deviated from ATC clearance However its a Resolution Advisory & ATC will need to be informed
I had one going in to LCA years ago and ended up tripping over my own tongue on advising ATC
Have searched in CAP 413 and other sources such as ACAS II Bulletin with no success

[Zenj]

Hi

We say

"ACAS CLIMB" or "ACAS DESCENT"

depending on wheather its a climb or descent


Zenj