Date: 201208
Local time of day: 0601-1200
Location: ZOA.ARTCC, CA
Flight conditions: VMC
Light: Daylight
Aircraft: Citation III; VI; VII (C650)
Operator: Fractional
Operating under: Part 91
Flight plan: IFR
Flight phase: Descent
Airspace: Class A ZOA
ATC / advisory: Center ZOA
Second aircraft: Regional Jet CL65; Undifferentiated or Other Model
Reporter organization: Fractional
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness; Time Pressure
Anomaly: ATC Issue All Types; Aircraft Equipment Problem Less Severe; Conflict NMAC
Detector: Person Air Traffic Control; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert; Flight Crew Took Evasive Action
Contributing factors: Incorrect / Not Installed / Unavailable Part; Procedure
Primary problem: Procedure

Narrative: We were cleared to descend from FL340 by Oakland Center. Descending through FL325; Center requested we maintain FL330. I; as pilot not flying; responded that we were passing FL322 and would he like us to return to FL330. Center Controller responded 'Yes; maintain FL330 and expedite'. We complied but even with a normal descent rate we were near FL310 by the time the pilot flying transitioned the aircraft from a descent to a climb. It was at this time that we got a brief Traffic Advisory (TA) but I cannot remember if the traffic was above or below. As we continued to climb toward FL330 we again received a TA from an aircraft I remember to be 800 FT above us. A visual scan identified a CRJ approaching from left to right and slightly above with a high rate of closure to our flight path. It became readily apparent that without an evasive maneuver on our part; a collision would occur.Concurrently; I commanded and the pilot flying executed; an immediate sharp left turn to avoid the CRJ as it passed off of our right wing at the same altitude. Once clear of the CRJ; we leveled at FL330. During these chaotic few moments; there was a radio exchange between the CRJ and ATC. ATC requested they maintain some alternate altitude but the CRJ declined stating they were following multiple RA's. The CRJ stated that they had received a CLIMB RA followed by a DESCEND RA. ATC then asked us what altitude we were at; to which I responded FL330 and added we had to take evasive action prior to leveling there. The CRJ then stated they believed they had originally been cleared to FL320 and wanted confirmation that was correct. ATC responded that they had been cleared to FL320 and said: 'My mistake'. From that point on; all communications were from a different controller. Shortly thereafter; we were switched to a new frequency and the flight ended without further incident.It appears this event occurred due to an unintentional mistake on the part of the Oakland Center Controller. Further exacerbating the issue was the lack of TCAS II on our aircraft. Had our aircraft been equipped with TCAS II; both aircraft would have been provided a resolution to the conflict irrespective of that offered by well meaning ATC. Having only TCAS I on our aircraft left us vulnerable to the chain of events that lead to this near miss. Without TCAS II; we could only follow the resolution offered by ATC until the traffic was visually identified and evasive action taken.Had we been in IMC or night conditions; we would not have had the advantage of identifying the conflict visually and I'm almost certain the outcome would have been catastrophic. In addition to the equipment issue; communication could have been better from the Controller. Had he stated: 'Traffic Alert' or something along that line; we may well have been more aggressive on the transition from descent to climb; understanding we were reacting to a threat rather than a simple altitude change.




Synopsis: A Citation flight crew experienced an NMAC when ATC failed to note their conflicting flight paths with a CRJ that was also descending.