Just today was shooting an approach with parallel runways. We were landing on the right side, general aviation aircraft landing on the left. ATC called the traffic on downwind and we knew he was going to be turning base leg putting him 90 degrees off our left coming at us. Had him in sight and sure enough we got our TCAS TA (traffic advisory) at about 350 ft. I want to see the final report on this deal and see if the voice recorder picked up a TA in the RJ cockpit. TCAS will not give a command for corrective action below 1000 ft, but it’s possible they got the TA off the helo at 350.