Incident
On an unspecified date, American Airlines Flight 1180, a McDonnell-Douglas DC-10, was 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 non-standard for its direction of flight. Both aircraft were operating under Instrument Flight Rules (IFR) in visual meteorological conditions (VMC). The airspace was non-radar and under the control of New York Air Route Traffic Control Center (ARTCC), with non-direct radio communications via ARINC.
Details
The two aircraft converged as they crossed over the ELWOD intersection. The VC10 passed in front of Flight 1180, from left to right, with less than the required IFR separation. Neither flight crew saw the other aircraft until Flight 1180 flew through the wake turbulence from the VC10. After encountering the wake, the crew of Flight 1180 observed the VC10 flying away at the same altitude, which they estimated was less than 1 mile distant.
ATC procedures at the time involved using flight progress strips. The strip for the VC10 was marked with a red underline and an arrow to indicate its non-standard altitude and direction of flight. The controller on duty stated that she was aware of the VC10 but did not see the strip for Flight 1180 in the bay for the ELWOD intersection. When the controller assumed her duty position, the previous controller had informed her that the VC10 was clear of conflicting traffic through the Stock, ELWOD, and DEENO intersections.