What happened
The incident occurred during the cruise phase of flight at the assigned altitude. The twin-engine aircraft experienced a sudden structural failure, breaking apart in mid-air. Following this catastrophic event, the wreckage impacted a farmland area located in Caernarfon. There was no opportunity for emergency landing or evacuation. All four individuals on board were killed in the crash. The occupants consisted of two pilots and two Air Traffic Control cadets serving as passengers.
Findings
The source material does not provide specific technical findings, investigation conclusions, or contributing factors regarding the structural failure. The record confirms the fatal outcome and the identities of the roles occupied by the victims, but no further causal analysis is available in the provided text.