ZHN center controller reported approach control handed off an aircraft that was on a conflicting cou...

Narrative:

I handed off a VFR aircraft at 2500 feet northeast bound entering approach's airspace. They took the hand off and I switched them. A minute later approach was flashing aircraft X to me at 2500 feet southeast bound about 15 miles from my airspace about 10 flying minutes away from my airspace. I took the hand off and continued to work my traffic. There was sequencing and 3 arrivals to phny; 2 doing practice approaches. Approach switched me aircraft Y at 2500 feet head on with aircraft X; that I had just switched to them still about 10 miles away from my airspace so I called the traffic and moved on with my other traffic areas.aircraft Y didn't have aircraft X in sight so I called the traffic again. They still didn't see the traffic. These two seemed to be on a collision course so I turned my aircraft left and descended the aircraft to avoid the traffic. I called approach to tell them what I did and I think they had the same idea but they turned the aircraft right so they were still on a collision course so I told them to turn their aircraft to the left to avoid the conflict. I determined that left would be the best course of action because it looked like my traffic would pass slightly north of them so a left turn wouldn't cross paths. I'm not sure the other controller would think otherwise. Eventually these aircraft passed with less than 200 feet and less than a mile. The proximity of these aircraft was very close and it all happened in approach's airspace and not in my sector so I shouldn't have been the one resolving this conflict! Also during the coordination when I called approach when I turned the aircraft I told them to turn their aircraft to the left to avoid collision their response was 'ok you know they are VFR right?' which as a safety minded professional is unacceptable!to avoid this kind of thing happening again aircraft should not be switched until all conflicts are resolved we had a head on situation where I was talking to someone and resolved a conflict not in my airspace. Approach should have held onto aircraft Y before switching it to me.

Original NASA ASRS Text

Title: ZHN Center Controller reported Approach Control handed off an aircraft that was on a conflicting course with VFR traffic and still inside the Approach sector airspace.

Narrative: I handed off a VFR aircraft at 2500 feet northeast bound entering Approach's airspace. They took the hand off and I switched them. A minute later Approach was flashing Aircraft X to me at 2500 feet southeast bound about 15 miles from my airspace about 10 flying minutes away from my airspace. I took the hand off and continued to work my traffic. There was sequencing and 3 arrivals to PHNY; 2 doing practice approaches. Approach switched me Aircraft Y at 2500 feet head on with Aircraft X; that I had just switched to them still about 10 miles away from my airspace so I called the traffic and moved on with my other traffic areas.Aircraft Y didn't have Aircraft X in sight so I called the traffic again. They still didn't see the traffic. These two seemed to be on a collision course so I turned my aircraft left and descended the aircraft to avoid the traffic. I called Approach to tell them what I did and I think they had the same idea but they turned the aircraft right so they were still on a collision course so I told them to turn their aircraft to the left to avoid the conflict. I determined that left would be the best course of action because it looked like my traffic would pass slightly north of them so a left turn wouldn't cross paths. I'm not sure the other controller would think otherwise. Eventually these aircraft passed with less than 200 feet and less than a mile. The proximity of these aircraft was very close and it all happened in Approach's airspace and not in my sector so I shouldn't have been the one resolving this conflict! Also during the coordination when I called Approach when I turned the aircraft I told them to turn their aircraft to the left to avoid collision their response was 'OK you know they are VFR right?' which as a safety minded professional is unacceptable!To avoid this kind of thing happening again aircraft should not be switched until all conflicts are resolved we had a head on situation where I was talking to someone and resolved a conflict not in my airspace. Approach should have held onto Aircraft Y before switching it to me.

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	1541298
Time
Date	201805
Local Time Of Day	0601-1200
Place
Locale Reference	ZHN.ARTCC
State Reference	HI
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	PA-28 Cherokee/Archer/Dakota/Pillan/Warrior
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	VFR Route
Flight Plan	VFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	VFR Route
Flight Plan	VFR
Person 1
Function	Enroute
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 7
Events
Anomaly	ATC Issue All Types Conflict Airborne Conflict

ZHN center controller reported approach control handed off an aircraft that was on a conflicting course with VFR traffic and still inside the approach sector airspace.