Yes - thank you, NSEU.

To get back to the original question, therefore, it seems the answer to bmbahia is twofold:

1) In the general case, there can be no implication to TCAS by setting QNH momentarily, unless it causes the aircraft to deviate from its vertical flight path, and

2) Specifically, on the A-320/330, this will never be so (vide FCOM 1.22.30).


JD
:)

Also I would assume the point 2) is valid for any FBW Airbus, from 318 to 380

Thanks, Pitcairn. :)

So not quite as easy as pushing one button on the CDU...

http://www.ozemail.com.au/~b744er/QFEon744.JPG