Sct controller did not specify the direction of turn to a fix and the descending aircraft turned the...

Narrative:

Aircraft X was VFR to myf told to stop at 6000 feet due to traffic at 5500 feet crossing. Aircraft Y was with a flight of four going to nkx. Because nkx runways were closed I was holding the flight of four at 13000 feet. Aircraft Y requested to depart the flight and proceed to nzy. I gave him a beacon code and started vectoring him to nzy and pointing him out to every sector that would be affected. He did not declare an emergency but I was handling it as if he needed to descend as soon as possible.aircraft X was still at 6000 feet about 3 miles from myf. Nkx tower; the flight of 3; and aircraft Y all called to let me know the runway is now open. Aircraft Y requests the overhead with the field in sight. I descend aircraft Y to 6000 feet and tell him resume own navigation to atlas (the initial for the overhead). I expect aircraft Y to loop north of nkx and make a right turn to join final. He proceeds to turn south downwind and make a left turn to final; which puts him in direct conflict with aircraft X who is still at 6000 feet. I tell aircraft X to start a descent immediately for traffic; which they do; and aircraft Y passes about 300 feet above them. Looking back I should have kept aircraft X completely south of the nkx final because he was unfamiliar and that would have kept him clear of the issue I was working out with the flight of fighters. Also; I should have told aircraft Y how I wanted him to enter the overhead. I assumed and it put both aircraft in a bad situation.

Original NASA ASRS Text

Title: SCT Controller did not specify the direction of turn to a fix and the descending aircraft turned the opposite direction resulting in a conflict with another aircraft.

Narrative: Aircraft X was VFR to MYF told to stop at 6000 feet due to traffic at 5500 feet crossing. Aircraft Y was with a flight of four going to NKX. Because NKX runways were closed I was holding the flight of four at 13000 feet. Aircraft Y requested to depart the flight and proceed to NZY. I gave him a beacon code and started vectoring him to NZY and pointing him out to every sector that would be affected. He did not declare an emergency but I was handling it as if he needed to descend ASAP.Aircraft X was still at 6000 feet about 3 miles from MYF. NKX Tower; the flight of 3; and Aircraft Y all called to let me know the runway is now open. Aircraft Y requests the Overhead with the field in sight. I descend Aircraft Y to 6000 feet and tell him resume own navigation to ATLAS (the initial for the Overhead). I expect Aircraft Y to loop north of NKX and make a right turn to join final. He proceeds to turn south downwind and make a left turn to final; which puts him in direct conflict with Aircraft X who is still at 6000 feet. I tell Aircraft X to start a descent immediately for traffic; which they do; and Aircraft Y passes about 300 feet above them. Looking back I should have kept Aircraft X completely south of the NKX final because he was unfamiliar and that would have kept him clear of the issue I was working out with the flight of fighters. Also; I should have told Aircraft Y how I wanted him to enter the Overhead. I assumed and it put both aircraft in a bad situation.

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.

Attributes
ACN	1408322
Time
Date	201610
Local Time Of Day	1201-1800
Place
Locale Reference	SCT.TRACON
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Small Aircraft High Wing 1 Eng Fixed Gear
Operating Under FAR Part	Part 91
Flight Phase	Descent
Flight Plan	VFR
Aircraft 2
Make Model Name	Fighter
Operating Under FAR Part	Part 91
Flight Phase	Descent
Route In Use	Visual Approach
Flight Plan	IFR
Person 1
Function	Approach
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 1
Events
Anomaly	ATC Issue All Types Conflict NMAC Deviation - Procedural Published Material / Policy

Sct controller did not specify the direction of turn to a fix and the descending aircraft turned the opposite direction resulting in a conflict with another aircraft.