[FabHK]

I wonder how many mid air collisions we would expect to see if see-and-avoid where entirely ineffectual, or pilots would not look outside ever except to land. I have the impression the accident numbers would not be much worse than they are.

In other words, my hypothesis is that the fact that there are few mid-airs is owed to ATC, technology (TCAS, TAS) and “big sky”, rather than vigilant pilots.

[ericpauley]

Agreed. It can be hard to spot traffic even if you know where the other plane is! With this in mind ADS-B/TIS-B seems like such an essential tool for GA pilots.