Sct TRACON controllers reported a controller forgot to issue a coordinated heading to an aircraft so...

Attributes
ACN	1443836
Time
Date	201704
Local Time Of Day	0601-1200
Place
Locale Reference	SCT.TRACON
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Medium Transport Low Wing 2 Turbojet Eng
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	Vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	PC-12
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	Airway V186
Flight Plan	IFR
Person 1
Function	Approach
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 6
Person 2
Function	Approach
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 23
Events
Anomaly	ATC Issue All Types Conflict Airborne Conflict Deviation - Procedural Published Material / Policy

Narrative:

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.

Original NASA ASRS Text

Title: 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.

Narrative: 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.

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.

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.