What happened
American Flight 1180, a McDonnell-Douglas DC-10, was traveling northbound over the Atlantic Ocean at flight level 350. Simultaneously, a British Royal Air Force Vickers VC10 was cruising eastbound at the same altitude, which was a non-standard altitude for that direction of flight. Both aircraft were operating under IFR rules within VMC, navigating through non-radar airspace under the control of New York ARTCC using non-direct radio communications via ARINC.
The two aircraft converged near the ELWOD intersection. During this convergence, the VC10 passed in front of Flight 1im80 from left to right, resulting in less than the required IFR separation. Neither flight crew observed the other aircraft until the crew of Flight 1180 encountered the wake turbulence produced by the VC10. Following this encounter, the Flight 1180 crew observed the VC10 flying away at the same altitude, estimating the distance to be less than one mile.
Findings
The air traffic controller reported being aware of the VC10; however, she did not see the flight strip for Flight 1180 in the bay for the ELWOD intersection. Upon assuming her duty position, the incoming controller had been informed by the previous controller that the VC10 was clear of conflicting traffic through the STOCK, ELWOD, and DEENO intersections.