What happened
On a day dedicated to air traffic control school exercises, two Avro Anson aircraft were operating in close proximity. The first aircraft, registered as EG251, was flown by a sole pilot. It was conducting a combined exercise with a second Avro Anson, registered NK380, which also carried one pilot. During the flight, the pilot of EG251 initiated a turn. As this maneuver began, the aircraft collided with the second plane. Following the impact, both airplanes lost control and dived into the ground near Uffington, Berkshire. The crash resulted in the total destruction of both airframes. Tragically, both pilots were killed in the incident.
Findings
The official investigation focused on the spatial awareness of the crew during the maneuver. It was determined that the pilot of EG251 initiated the turn without having an accurate knowledge of the precise position of the second aircraft. This lack of situational awareness regarding the other plane's location led directly to the mid-air collision.