Originally Posted by
Zar_1
What I implied was, that TCAS INOP should be a non-dispatchable condition... of course, a ferry flight would be permitted... but really though, considering how 'see and avoid' is clearly deficient at modern airliner speeds, and under high workloads, is it really safe to dispatch a flight without a working EGPWS/TCAS ?
Aviation has reached such heightened levels of safety, owing a lot to the automation and safety systems, which serve to significantly enhance Sit. Awareness... and permitting revenue flights without them, IMO, is a mistake.
Is there a particular accident you are referring to, where a TCAS or TAWS system was MEL'd and the crew had a bad day? The primary means of traffic and terrain separation (well, departure can be slightly different) is ATC, then alerting, then a pilot that is competent and awake.