TCAS and Range Selection
I am wondering why the CVR transcripts so far fail to show either crew questioning ZRH about the converging TCAS symbol at same altitude, or any cockpit discussion before the traffic alerts.
With courses converging at nearly 90 degrees, the TCAS symbol for the other a/c should have shown on the display at 45 degrees off the a/c track plus or minus the 15 degrees azimuth error.
I speculate that a typical en route range selection of 160 or 320 miles on the ND would compress TCAS symbols in a way that would make it difficult to sort out potential threats from non-threats.
Would it be useful to momentarily override the range selection on one of the NDs or EICAS when another a/c approaches within the limits for proximity intruder traffic (<1200 ft and/or 6nm) or even earlier?
This would give the crew a bit more time to query ATC and get ready for a TA.