Tu154 Crew not listening out?
Whippersnapper
RE: "154's apparent failure to respond to radio or TCAS. "
The UNCTUOUS Post on Page 10 (of this thread) addresses this point quite effectively.
The CHIRP about the Radio Management Panel (RMP) explains it all to me - and quite satisfactorily (and the CVR might amplify this). The Russian pilots possibly got a call from the galley about "what meals they each wanted" (and of course because captain and copilot have to eat different meals, they would have both been on intercom (and off the ATC VHF monitors automatically, courtesy of the glitch in most aircraft's RMP setup - as described in the CHIRP).
The key to the accident is the missed first and second calls and their response to the urgent third ATC call (but by that time the 757 was in urgent TCAS RA avoidance action and the Russian pilots simply followed ATC instructions, negating the 757 TCAS's RA solution). I would suggest that as it would now appear that the Tu-154 is TCAS equipped, it was that cooking off of the initial TA over the cockpit speakers (and in any headsets they had on) that alerted the Russian pilots - and they then went for the radio Tx/Rx buttons because a 90 degree crossing angle is absolutely the worst for visual acquisition, particularly at night, and they couldn't see the conflicting a/c.
Once they'd re-selected their VHF radios they caught that third urgent ATC instruction. AND THEN, not realising that it was the THIRD (not having heard the first two), they quite reasonably followed the ATC urgent instruction to descend (which by that time was so stale as to be useless). A major glitch with TCAS is that, as in this case, you can have ATC and TCAS working in ignorance of each other (and fatally, against each other). As a last minute J.I.T. (just in time) system it leaves much to be desired. There is also a major glitch between TCAS II variant 7 and earlier TCAS II's (that may well have played a part). The TCAS 2000 use of mode S to give lateral avoidance solutions would be an improvement because any turn will also provide a beautiful visible planform to the other crew (instead of a head-on dot or an oblique profile).