"Guy Elden Jr" wrote in message
oups.com...

Something I've always wondered... why do TRSAs even exist?


Good question. Nobody seems to know the answer.



Seems like a dangerous proposition to choose some airports as having the
concept of a voluntary controlled airspace?


What seems dangerous about it? TRSAs exist in Class D and Class E airspace
but are not in themselves controlled airspace.



Why not a Class C (their closest
cousin as far as I can tell)?


Part of the Airport Radar Service Area (ARSA) plan was to eventually replace
all TRSAs with ARSAs, which are nor Class C airspace. But not all TRSAs met
ARSA requirements.