What happened
During a night navigation exercise departing from RAF Penrhos, the flight crew encountered deteriorating meteorological conditions. The visibility dropped significantly, creating low-visibility conditions for the twin-engine airplane. Unable to maintain safe separation from the terrain in these conditions, the aircraft impacted the slope of Mount Foel Gron, which is located east of Salem.
All five members of the crew were on board at the time of the accident. Four crew members were killed instantly upon impact. One other crew member sustained serious injuries and was transported for medical treatment but died the following day due to those wounds. The incident resulted in a total of five fatalities.
Findings
The official investigation concluded that the accident was caused by a controlled flight into terrain. This determination indicates that the aircraft remained under the control of the crew until it struck the ground, likely due to the inability to visually identify the terrain features in the low-visibility night conditions.