What happened
A Federal Express DC-10-10F and an American International Airways Lockheed L-1011-385-1-15 experienced a near mid-air collision approximately 30 miles west of Salina, Kansas. The two aircraft maintained the same altitude, with an estimated horizontal separation of only 1/2 mile.
The crew of the Lockheed L-1011 reported seeing the DC-10 at their 8 o'clock position at a distance of 1/2 mile, prompting the first officer to turn the aircraft 30 degrees to the right. The pilots of the Federal Express aircraft reported that they did not visually identify the Lockheed L-1011 but did feel its wake turbulence.
Both aircraft became NORDO (no radio) during the encounter. Air traffic control attempted several methods to reestablish radio communications with both flights but was unsuccessful.
Findings
A Final Operational Error/Deviation Report from the FAA identified two primary errors by air traffic controllers. First, one controller dropped the data block for FDX3207 without transferring communications to another controller. Second, another controller issued an incorrect frequency change to CKS303, directing the crew to 125.67 instead of the correct frequency of 127.65; the crew of CKS303 correctly read back the incorrect frequency.