Incident Overview
A McDonnell Douglas DC-10, operating as Viasa Flight 800, and an Airbus A310, operating as Pan Am Flight 221, were involved in a near collision while on international flights over the Atlantic Ocean. Both aircraft were flying under instrument flight rules (IFR) on airway Amber 300 in a non-radar environment without direct radio contact with an air traffic control (ATC) facility. Communication between the aircraft and ATC was relayed through ARINC, a commercial company.
Sequence of Events
Pan Am Flight 221 was southbound at flight level (FL) 370 when it requested, via ARINC, to climb to FL 390. The controller at New York Center Oceanic Control received the request, coordinated with San Juan ARTCC, scanned his board, and, seeing no conflicts, approved the climb. After leveling at FL 390, Flight 221 converged head-on with Viasa Flight 800, which was northbound at the same altitude.
Evasive Action and Separation
The aircrew of Viasa Flight 800 took evasive action to avoid a collision, while the crew of Pan Am Flight 221 elected not to maneuver. The captain of Viasa Flight 800 estimated that the aircraft passed with 500 to 1,000 feet of horizontal separation and 350 feet of vertical separation.
Controller and Flight Strip Handling
The controller had just come on duty. After Viasa Flight 800 had previously passed a mandatory reporting point, its flight strip had been removed from the controller's board, as the next intersection was a non-reporting fix.