A little yellow blob on a screen with a relative height readout and an audio warning could easily have saved four lives.
Having been through the military fighter pilot training thing early in life, the whole 'lookout' is good training but ultimately hampered by human limitations.
Agree - but it's not just
human limitations. I've yet to fly a GA type that doesn't block off your view in some directions, even the Tiger Moth. Cessnas stop you seeing above, Pipers ditto below, unless you manoeuvre frequently - which of course we all do for HASELL, but probably not so much the rest of the time. I try my best to spot the other guys, but I do know that a
"little yellow blob and an audio warning" have made my life more comfortable several times. Just as it seems sound sense to take a sextant as well as a GPS when I sail long distance, so I switch on TCAS
and keep a decent lookout when I'm airborne. I'm not sure that's a strong enough argument for making some kind of collision avoidance technology compulsory; but that's a different argument.