A CESSNA TR182 PLT RPTS AN NMAC WITH ANOTHER CESSNA IN THE SBP TFC PATTERN.

Narrative

THE PROB BEGAN WITH MY RPTING MY POS INCORRECTLY WHEN INITIATING MY CALL TO TWR AT 9 MI OUT. I SAID I WAS SW WHEN I WAS REALLY S OF THE ARPT. TWR INSTRUCTED ME TO MAKE A DOWNWIND TO RWY 29. I DSNDED IN ORDER TO MAKE A 45 DEG ENTRY TO DOWNWIND. TWR RPTED THAT THE CESSNA WHICH HAD JUST TAKEN OFF AND WAS ON XWIND WOULD BE DEPARTING DOWNWIND. I HAD THE CESSNA IN SIGHT AND; EXPECTING HIM TO TURN DOWNWIND; TOLD TWR I'D TURN IN BEHIND HIM. THE CESSNA NEVER DID TURN DOWNWIND; HOWEVER; AND CONTINUED TO CLB OUT ON XWIND. WE CAME VERY CLOSE TO COLLIDING ON THE EXTENDED XWIND. I MADE A STEEP R BANK EVASIVE MANEUVER TO AVOID HITTING HIM. HAD I RPTED MY POS TO TWR CORRECTLY TO BEGIN WITH; I PROBABLY WOULD HAVE RECEIVED A STRAIGHT-IN AND THIS WHOLE SIT WOULD HAVE BEEN AVOIDED. AS I WATCHED THE CONFLICT DEVELOP; I SHOULD HAVE BEEN AGGRESSIVELY ON THE RADIO TO TWR TO CLARIFY THE OTHER PLANE'S INTENTIONS; RATHER THAN ASSUMING THE CESSNA WOULD TURN. THE OTHER PLANE SHOULD HAVE GOTTEN ON THE RADIO WHEN HE CHANGED HIS MIND ABOUT HIS DEP. HAD HE ANNOUNCED HIS INTENTION OF CONTINUING W FOR DEP; RATHER THAN MAKING THE DOWNWIND DEP; I WOULD HAVE TURNED DOWNWIND EARLIER AND AVOIDED THE NEAR MISS. TWR CLAIMED IT NEVER SAW ME DUE TO MY RPTING MY ORIGINAL POS INCORRECTLY. TWR DIDN'T TALK TO THE DEPARTING PLANE OR ME ABOUT THE CONFLICT AS IT DEVELOPED.