The last 214ST I touched at PHI  

was circa 2001.  We were just starting to install Skywatch in 206's and 407's.  Pretty sure the 214's we had never got skywatch.  We sold them off as is, they were old and beginning to show signs of their age.  92's replaced them....the few we had.  SO yeah, if we didn't install any sort of TCAS back then, I doubt anyone else bothered to put it in either.  Owners probably figured working fires meant remote work and out there all alone with not much traffic around to be worried about triggering a traffic alert anyway.  It's not like you are ever gonna fight fires in Class B airspace.

We put skywatch in for the GOM birds....because let's face it.  With out it, you guys would probably have run into each other at least once a month.