Originally Posted by ByrdluvsAWACO
Yes they are linked, but not as tight as you're implying. The original HP(Hawaiian Pacific) certificate didn't have the callsign 'cactus'. That change was done way after America West began flying.
America West can just as easily request that the call sign "cactus" be assigned to the US certificate.
They could certainly do that, or put any other available callsign on the certificate. I was simply answering the question of what a certificate had to do with a callsign.