Date: 201902
Local time of day: 1801-2400
Location: ZNY.ARTCC, NY
Aircraft: Large Transport; Low Wing; 2 Turbojet Eng
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class A ZNY
ATC / advisory: Center ZNY
Second aircraft: Widebody Transport
Reporter organization: Government
Reporter function: Enroute; Oceanic
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Human-Machine Interface; Situational Awareness; Troubleshooting
Anomaly: ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued New Clearance
Contributing factors: Procedure; ATC Equipment / Nav Facility / Buildings
Primary problem: Procedure

Narrative: I took over the position prior to the event from a trainer and his trainee. After sitting there for a few minutes and scanning the strips I noticed something that looked a little peculiar to me. Aircraft X was coordinated northbound on L455 to SAVIK at FL340 and Aircraft Y was coordinated westbound direct to CROAK at FL340. Upon seeing this I called the controller working the eastern adjacent non-radar sector requesting him to draw out the routes of the two aircraft on his Geographical Display and advise me what he thought about the two aircraft and their separation. His assessment was that the cross for these two aircraft happened inside of radar airspace; and ATOP (Advanced Technologies Oceanic procedures) did not show a conflict; but that it did appear unsafe to him.I then got on the line with the controller working the southern adjacent non-radar sector to take a look at the two aforementioned aircraft; telling him that I did not like the way they looked. He agreed and we implemented a plan to achieve what we agreed would be a safer solution. Aircraft Y was descended to FL330. As far as I am aware; these two aircraft never experienced a loss of standard separation. Regardless; had these aircraft flown at the same altitude; in my opinion; there was no non-radar separation being appropriately applied. [The track data] was reviewed and the aircraft appeared to have a maximum of 8.82 miles between them just south of SAVIK. At SAVIK there is no guarantee that the radar sector at 86 will have radar contact nor communication with these two aircraft.This was an unsafe situation most likely due to the radar sector assuming that ATOP was probing the aircrafts' profile further into radar and the non-radar sectors not being aware to it due to the southern adjacent non-radar sector only having the data block of Aircraft Y pop up as I called them; and the eastern adjacent non-radar sector never having the opportunity nor reason to know about Aircraft X. This conflict should be detected and displayed by ATOP. Had Aircraft X been 1 minute later; or the Aircraft Y been 1 minute early there definitely would have been a loss of standard separation; as I believe they would have had less than 5 miles laterally with no altitude separation. This was unsafe; and I recommend that ATOP be changed to detect and display the conflict.




Synopsis: ZNY Oceanic Controller reported detecting a potential conflict with two aircraft that was not predicted by ATOP.