Anytime TCAS activates in the "RA region", it should be mandatory for both planes to report it to the FAA as "significant". No exceptions. And it should be thoroughly investigated. It's absurd to rely on airlines to "self-police".<p>Fortunately things aren't nearly as bad as 50 years ago. Here's [1] a horrible accident that led to modernized ATC.<p>[1] <a href="http://en.wikipedia.org/wiki/1956_Grand_Canyon_mid-air_collision" rel="nofollow">http://en.wikipedia.org/wiki/1956_Grand_Canyon_mid-air_colli...</a>