Dash 8-300
Flight Crew Air Transport Pilot (ATP)
Conflict Airborne Conflict
Flight Crew Took Evasive Action
Procedure
While being vectored for approach; we received a TCAS RA directing us to climb after having received a TCAS TA. We immediately climbed by approximately 700 ft until the TCAS system stopped giving us a climb command. We notified approach of the TCAS RA and that we were in a climb. Once the command ended; we returned to our previously assigned altitude and advised Approach. We didn't see the TCAS intruder until we began our climb; it appeared to be a single engine aircraft at a VFR altitude of approximately 4;500 ft. We had been assigned a vectoring altitude of 5;000 ft. After we returned to our previously assigned altitude; the rest of the flight was uneventful.
Single engine; westbound GA aircraft was 400 ft lower than us and caused the TCAS RA alert. I turned off the autopilot and climbed 700 ft as per the RA.The system worked well in detecting a possible conflict; issuing the RA and then announcing clear of conflict.
DHC-8 flight crew reported a TCAS RA for unreported traffic while on approach.