Light transport aircraft pilot reported an near midair collision on approach into cma airport.

Attributes
ACN	1581616
Time
Date	201809
Local Time Of Day	1201-1800
Place
Locale Reference	CMA.Airport
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Light Transport Low Wing 2 Turbojet Eng
Operating Under FAR Part	Part 135
Flight Phase	Descent
Route In Use	Direct STAR GUERA 2 RNAV
Flight Plan	IFR
Person 1
Function	First Officer Pilot Flying
Qualification	Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument
Experience	Flight Crew Last 90 Days 60 Flight Crew Total 5500 Flight Crew Type 950
Events
Anomaly	Conflict NMAC
Miss Distance	Horizontal 1 Vertical 400

Narrative:

We were descending via the guera 2 arrival into cma. After crossing janny waypoint and handed off to socal approach control from joshua approach. Socal cleared us direct to suana waypoint and to descent to 6;000 ft from 8000 feet. During the descent to 6;000 feet; socal advised us of traffic at our 11 o'clock position. As we passed through approximately 7;500 feet; we received the TA which turned into a RA and commanded a climb. We immediately followed the RA command to climb. As we passed through 7;600 feet after stopping the descent; we saw the traffic above us approximately three to four hundred feet above us. We were then commanded to initiate an immediate descent. Once the avoidance maneuvering ended; we advised ATC of the incident and returned to our assigned altitude of 6;000 feet.

Original NASA ASRS Text

Title: Light Transport aircraft pilot reported an NMAC on approach into CMA airport.

Narrative: We were descending via the GUERA 2 arrival into CMA. After crossing JANNY waypoint and handed off to SOCAL Approach control from Joshua approach. SOCAL cleared us direct to SUANA waypoint and to descent to 6;000 ft from 8000 feet. During the descent to 6;000 feet; SOCAL advised us of traffic at our 11 o'clock position. As we passed through approximately 7;500 feet; we received the TA which turned into a RA and commanded a climb. We immediately followed the RA command to climb. As we passed through 7;600 feet after stopping the descent; we saw the traffic above us approximately three to four hundred feet above us. We were then commanded to initiate an immediate descent. Once the avoidance maneuvering ended; we advised ATC of the incident and returned to our assigned altitude of 6;000 feet.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.