What happened
A private flight involving a pilot and three passengers was conducting a cross-country trip over the ocean in a Mitsubishi MU-2B. For approximately two and a half hours, the aircraft maintained a steady altitude at FL240, consistent airspeed, and a constant heading. During this period, radar contact with the aircraft was lost.
At the time of the disappearance, meteorological notices had been issued for the region, warning of frequent thunderstorms with cloud tops reaching FL400. Satellite data confirmed significant convective activity in the vicinity. The area was also subject to conditions involving moderate or greater icing and the presence of supercooled large drops. While the wreckage was not recovered for physical inspection, the disappearance of the radar target, combined with the discovery of debris and a fuel sheen on the ocean surface, indicates the aircraft likely entered an uncontrolled descent and struck the water.
Findings
Investigations into the pilot's experience revealed that while the pilot had met the regulatory requirements for acting as pilot-in-command of the Mitsubishi MU-2B, much of this experience was recent. The pilot had accumulated approximately 120 total multi-engine hours, with 100 of those hours logged in this specific model over a single month of intensive training. While described as an attentive student, it was unclear if the training was sufficiently ingrained for solo operational use in adverse conditions.
Regarding environmental factors, a hazardous weather advisory regarding convective activity was broadcast by air traffic control roughly 25 minutes before the loss of contact. Although sufficient information was available to anticipate thunderstorms and icing, there was no evidence in the radar track or radio communications that the pilot attempted to deviate from the flight path to avoid these hazards. Additionally, while evidence suggested the pilot may have been suffering from a lack of restorative sleep, the impact of fatigue on the flight's outcome could not be definitively determined.