Regional Jet 200 ER/LR (CRJ200)
Flight Crew Air Transport Pilot (ATP)
Situational Awareness
Aircraft Equipment Problem Less Severe; Conflict Airborne Conflict; Deviation - Altitude Excursion From Assigned Altitude
Flight Crew Took Evasive Action
Aircraft; Human Factors; Weather
Climbing out of ZZZ through approximately 5;000 ft MSL for 17;000 ft MSL. ATC advised us of traffic at our 12 o'clock; a Cessna at 9;500 MSL; VFR. We responded that we were looking for the traffic. Unable to get the traffic in sight; ATC had us stop the climb at 9;000 ft MSL. We leveled at 9;000 ft MSL with the autopilot on. I told the FO we may get a TCAS RA and to be ready. We kept searching for the traffic but with the haze we did not get the traffic in sight. We then got a TCAS TA; a few seconds later we got a TCAS RA to 'climb; climb'. We disconnected the autopilot and began a climb per the SOP. We advised ATC that we were climbing in response to a RA. She advised the traffic was directly above us. At approx. 9;300 ft MSL the RA switched from climb to 'descend; descend'. We then reduced power and descended to 9;000 ft MSL. As we began the descent; we got visual contact of the traffic that was passing off our right and was no factor. We advised ATC the traffic was in sight. She then climbed us to 17;000 ft MSL. We continued the flight as normal.The restricted visibility due to haze and the inability to get the traffic insight visually. Another factor I believe is the TCAS gave us a RA initially of 'climb; climb' because the other aircraft was not TCAS equipped. When our TCAS saw the other aircraft go from 9;500 to 9;400; it wanted us to climb above him since he was descending into us. With the other traffic only 500 ft above our current altitude of 9;000 ft; we could have asked ATC for a lower altitude or a turn off course. Also; if the other aircraft were TCAS equipped he would have been issued an opposite RA from ours.
Apparently; since the TCAS could not communicate with the GA target; the TCAS initially picked the wrong course of action.
CRJ-200 flight crew reported a traffic conflict that initially resulted in less than optimum guidance from the TCAS system presumably due to the fact the other aircraft was not TCAS equipped.