Date: 201501
Local time of day: 1801-2400
Location: ZWY.ARTCC, NY
Light: Night
Aircraft: Large Transport
Operator: Air Carrier
Operating under: Part 119
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class A ZWY
ATC / advisory: Center ZWY
Second aircraft: Large Transport
Reporter organization: Government
Reporter function: Enroute; Oceanic
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Time Pressure; Situational Awareness; Distraction; Confusion; Communication Breakdown; Troubleshooting
Anomaly: ATC Issue All Types; Conflict Airborne Conflict; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Separated Traffic; Air Traffic Control Provided Assistance; Air Traffic Control Issued New Clearance
Contributing factors: Procedure
Primary problem: Procedure

Narrative: I have been a controller at ZWY Area E for over [time period deleted] years; and as such; have worked the WATRS airspace through its various forms: non-radar; non-radar with ODAPS (Oceanic Display and Planning System); and ATOP non-radar. I was working the off-shore radar sector Rac82/83 during the day shift. This radar sector manually coordinates with the D88 ATOP controller; feeding the radar traffic to the non-radar controller. Aircraft X had been coordinated down L452; which is parallel to L453; and prior to OXANA; Aircraft X's radar service had been terminated. Alongside Aircraft X; on the parallel airway L453; was Aircraft Y. Both aircraft were at FL370. Aircraft X progressed OXANA at XX00Z. Shortly after that; I noticed Aircraft X's track was proceeding along M325; and not L452. I called Aircraft X in the blind and asked another flight to attempt contact through company channels. In addition; I asked the D88 controller to call Commercial Radio and have the flight contact me. On any other sector I would have attempted contact on Guard; but R82/83 has no guard frequency transmitter!  I could have asked one of the other flights to transmit on Guard to contact Aircraft X; but as circumstances worked out; I didn't need to (such a procedure is more time consuming; since you must explain to the assisting flight exactly what you need; and time was of the essence). Aircraft X was proceeding towards ONGOT; which Aircraft Y was also proceeding towards. They had less than one minute converging at ONGOT. Southeast-bound M325 traffic and southbound L453 traffic require fifteen minutes crossing to be separated. The situation was thus: at best; had I taken no action; we had a 93% loss of separation; at worst; a mid-air collision. Aircraft Y; whom I was still in contact with; was south of PAEPR; and rapidly leaving radar airspace.  I issued a heading of 230 to Aircraft Y both to keep the flight in radar and point Aircraft Y at Aircraft X; thus ensuring that they would miss each other. I later turned Aircraft Y further right to heading 240. Commercial Radio contacted Aircraft X and told the flight to call me on VHF; which Aircraft X did. Once I had contact with Aircraft X; we determined that their flight plan did not match what was in our Flight Data Entry Printout. I established degrees divergence between Aircraft X and Aircraft Y using vectors; and sent them back onto what we had originally shown their routes to be: L452 and L453. My actions prevented any loss of separation. FLM (Front Line Manager) [name removed] looked into the situation and his preliminary investigation pointed to the tower activating the wrong flight plan; which was entirely identical up until OXANA; so there was no earlier opportunity to discover the discrepancy. FLM [name removed] filed a report. Aircraft X told me they had been issued several code changes; and had ultimately ended up back on their original code. While this is not positive proof of a flight plan discrepancy; it is a common occurrence when there is a flight plan discrepancy. Most disturbing in this situation is that ATOP received a position report from Aircraft X; progressing OXANA; estimating NETSS; and ONGOT next.  This is out of conformance with the L452 routing that ATOP was showing; but ATOP did not issue an out of conformance message. I believe this is due to the ATOP-radar present position report being within the lateral bounds of L452 when the message was sent. In a fully non-radar situation; ATOP will inform the controller if a position report is out of conformance; route-wise; if the present position is outside of parameters; or if the next position is outside of parameters; or if the ensuing waypoint is outside of parameters. Here; because of the ATOP-radar; the ATOP did not report the next position or ensuing waypoint as out of conformance; which they were by a dangerous margin. This is unsafe. Also unsafe is the lack of a Guard transmitter with R82/83. Other possible solutions for avoiding a reoccurrence of this type of dangerous situation: R82/83 controllers being required not to terminate radar north of OXANA or PAEPR (a practice which I have now adopted); Flights issued multiple code changes and are heading into WATRS or Oceanic airspace might be advised to ask for a routing confirmation; coordination between R82/83 and D88 being mandated to be effected at ZZTOP; NETSS; and SAUCR (as opposed to OXANA/PAEPR); which would have caught this error.




Synopsis: ZWY Controller describes a situation where two aircraft that he was responsible for were on a course to collide. Controller separated traffic.