What happened
On a scheduled 15-hour training mission, two aircraft departed from RAF St Eval at 10:14 local time. The second aircraft, an Avro Shackleton MR.2 with registration WL743, took off six minutes after the first. Both aircraft were operated by the 42nd Squadron and carried nine crew members each.
At 20:58 local time, the final radio communication was received from the aircraft. Two minutes later, both planes vanished from radar at the same time. Extensive search and rescue operations were launched to locate the missing vessels; however, these efforts were halted several days later after no wreckage or survivors were located. The incident resulted in 18 fatalities.
Over a decade after the disappearance, a piece of debris was recovered. A fisherman discovered the fourth engine from the WL743 aircraft caught in a fishing net, approximately 75 miles north of where the mid-air impact was suspected to have occurred.
Findings
Official investigations were unable to confirm the specific circumstances due to a lack of physical evidence. However, investigators concluded that the disappearance was likely caused by an in-flight collision occurring during conditions of limited visibility.