I was very surprised to hear (and please confirm?) that freight aircraft are not affected by the FAA directive on TCAS installation. I'm surprised because one would think that a collision involving, for example, a UPS 747 would do a lot more damage than one involving a small passenger commuter plane, like a Saab 340. Is this correct and why were freight aircraft not included?
(I'm assuming that aircraft delivered new to UPS and Fed Ex, such as the 767s and A300s, as well as the reworked MD10s, would have TCAS installed anyway?)
A question for pilots: is there any circumstance where a technical problem could cause the TCAS to become u/s? If so, what would happen in that case? Would the flight have to divert? Presumably the FAA would take a severe view if an aircraft was dispatched with the TCAS inop?