LTT ON APCH HAS NMAC WITH SMA.

Narrative

WE WERE HANDED OFF FROM APCH CTL TO THE TWR WHILE ON A 3- 4 MI FINAL. TWR CLRED US FOR LNDG AFTER WE CHKED ON FREQ. WE WERE FOLLOWING TFC (WHICH WAS NO FACTOR) WHICH WAS OVER THE APCH LIGHTS FOR RWY 32. WHEN WE WERE ON 1-1 1/2 MI FINAL; TWR CLRED ANOTHER CARRIER (SAAB 340) FOR TKOF FROM A XING RWY (23). THE FO AND MYSELF DISCUSSED THE POSSIBILITY OF DOING A GAR IF THE XING TKOF TFC DID NOT EXPEDITE THEIR TKOF. ABOUT 30 SECONDS ELAPSED FROM OUR DISCUSSION WHEN THE FO STATED; 'TFC AT 1230-1300 O'CLOCK (PAUSE) GAR!' I INITIATED A GAR AND AS I WAS DOING SO I SAW THE TFC THROUGH THE FO'S WINDOW. I HAD TO USE EVASIVE MANEUVERS TO AVOID HITTING THE OTHER ACFT. (STEEP CLBING LEFT TURN) THE BANK ANGLE WAS APPROX 45-60 DEGS. THE FO NOTIFIED THE TWR WE WERE DOING A GAR TO AVOID THE TFC WHICH WAS A CESSNA 152; BLUE ON WHITE; WHO WAS ON A R BASE TURNING FINAL. TWR DID NOT SAY ANYTHING EXCEPT THAT THE TURN WAS APPROVED AND CLRED US TO LAND AGAIN. THE MAJOR CAUSE TO THIS INCIDENT WAS NO COM FROM ATC. ONCE WE CHKED ON WITH THE TWR THEY NEVER TOLD US ABOUT THE CESSNA IN THE PATTERN DOING TOUCH AND GOES NOR WAS THERE ANY CALLS FROM THIS CESSNA. ONE OF THE MAJOR FACTORS THAT AFFECTED THIS FLT WAS THE DISCUSSION BY THE CREW OF A POTENTIAL GAR WHICH GAVE US AN EDGE. EVEN A SPLIT SECOND EDGE THAT HELPED US TO AVOID THE CONFLICTING TFC. IF WE DID NOT HAVE THIS DISCUSSION WE MIGHT HAVE HAD A MID-AIR COLLISION. I TALKED TO THE SUPVR WHO WAS ON DUTY AND AFTER A SHORT INVESTIGATION HE NOTIFIED US THAT THE CTLR MADE A MISTAKE AND ALSO THE CESSNA. WE WERE TOLD THAT THE CESSNA WAS TO EXTEND DOWNWIND AND DID NOT. ATC WAS GOING TO QUESTION THE PLT IN THE CESSNA.