Mir From , joined Dec 1969, posts, RR:
Reply 2, posted (5 years 7 months 1 week 2 days 2 hours ago) and read 2527 times:
Quoting Faro (Thread starter): From aircraft registration sites, the impression one gets is that these codes are specific to an airframe and do not change from one operator to the another. Is this the case, and why?
It is the case, though there are now duplicate codes out there (though I think they try to separate the duplicates geographically). As for why, I'm not really sure. It shouldn't be too hard to have ATC assign the codes when necessary.
Having duplicate codes is not a big deal - even if you do have two aircraft with the same SELCAL code flying in the same airspace, all that will happen is you'll have both aircraft check in when you send a call out. You give the message to the one you wanted to, and just tell the other "sorry, wrong number".