Medium Transport; Low Wing; 2 Turbojet Eng
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 6
Situational Awareness; Confusion
ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance; Air Traffic Control Separated Traffic
Airspace Structure; Human Factors; Procedure
Aircraft X was coming from the east landing Runway 33 at BUR. Aircraft Y was southbound on V459 landing HHR. There was an IFR GA plane at 6000 feet in front of Aircraft X and numerous VFR aircraft headed westbound to CMA. The handoff to sector for a HHR arrival is 7000 feet on a 140 heading in the vicinity of DARTS. The routing the aircraft is issued is V459 DARTS V186. Once I saw Aircraft Y would pass in front of Aircraft X I switched Aircraft Y to Stadium. I forgot to issue the 140 heading after DARTS; so Aircraft Y made a left turn at DARTS towards Aircraft X. When I saw Aircraft Y start the left turn I realized my error and turned Aircraft X to the right. Stadium also noticed and told me they were turning Aircraft Y south. I'm not sure if 3 miles was kept until they turned away from each other. This situation has happened before with aircraft to HHR; it might be a good idea to change the routing HHR arrivals are issued so they don't turn left at DARTS. This change was made a couple years ago for LAX arrivals that have the same handoff to Stadium.
Aircraft Y was on route to HHR. I believe the filed route has them turn at DARTS - V165 eastbound. However the Glendale sector issues them a 140 heading after DARTS and then my sector vectors them to the HHR final. I always issue fly present heading or heading 140 on initial contact just in case Glendale forgets. Glendale had crossing traffic westbound at 6000 feet so they held on to Aircraft Y until that conflict was resolved. I'm guessing that Aircraft Y had not been given the 140 heading because when he checked in he was turning eastbound on the airway. I turned Aircraft Y south to a 180 heading to correct this. That's when I noticed Aircraft X westbound on the airway at 7000 feet. I advised Glendale that Aircraft Y was turning to a 180 headingI've seen this turn happen dozens of times. I'm not sure how this can safely be fixed.
SCT TRACON Controllers reported a Controller forgot to issue a coordinated heading to an aircraft so it turned on its filed route into confliction with other traffic.