Gulfstream G200 (IAI 1126 Galaxy)
Flight Crew Air Transport Pilot (ATP)
Situational Awareness
ATC Issue All Types; Conflict NMAC; Deviation - Altitude Excursion From Assigned Altitude
Flight Crew Took Evasive Action
Human Factors; Procedure
Flying under IFR and on a heading vector from SoCal to VNY at 5;000 feet. The Pilot Flying (PF) observed traffic on the TCAS that was approaching from about 10 o'clock position. The PF started the search for the traffic and alerted the Pilot Not Flying (PNF) the traffic was not in sight. The traffic got closer and a TA was received. PF continued to look for the traffic and without locating it the RA was received to descend. The PF initiated a descent and slight turn to the right to avoid the traffic.  As the RA was received SoCal alerted us we had traffic and to turn left. This would have put us in direct conflict with the traffic. The resolution commenced and the 'clear of conflict' was received. The RA resulted in about a 1;000-1;200 foot descent. The PNF made a radio call to SoCal to alert them of our RA. SoCal gave us a climb to 5;000 Feet and a turn left to a heading 330. The instructions seemed to be in direct conflict with 2 other targets. One at our approximate 12 o'clock and about 700 feet above us. The other at our 10 o'clock and approximately 600 feet above us. Both targets appeared to be within about 3 miles of our position.  The PF asked the PNF to query SoCal the instructions again. The PF stayed at 4;000 feet and started a shallow banked turn to the left. SoCal was busy and it was hard to get a word in. PNF asked twice for SoCal to repeat the heading. Finally the instructions were given again to expedite our climb to 5;000 and turn left to heading of 330. While in the climbing turn we received another TA from the traffic at our 10 O'clock position. The TCAS showed it 300 feet above us and slightly off our left wing. The PF looked out and saw an aircraft pass to our left and slightly behind us approximately 300-400 feet away from our aircraft; to our recollection. Neither of the 2 possible targets were ever pointed out to us. We were handed off to another controller where the PNF reminded that controller that we were climbing back to 5;000 Ft. / on a heading due to an RA. We were radar vectored onto the ILS for 16R at VNY. The crew could have tried to query ATC about the approaching conflict.
G200 First Officer reported NMAC on a flight into VNY and indicated ATC was not much help in situational awareness and mitigation.