What happened
The aircraft was conducting a maritime patrol mission over the Atlantic Ocean. Following the completion of the mission, the crew began their return journey to base. Upon approaching the destination area, the flight encountered deteriorating weather conditions that reduced visibility.
Unable to proceed with an instrument approach due to the lack of available equipment at the time, the captain elected to attempt a visual approach. The aircraft circled the base in an effort to wait for improved visibility. During the descent phase, while at an altitude of 800 feet, the seaplane collided with the slope of a mountain situated near Krísuvík, approximately 25 kilometers southeast of Keflavik Airport.
The impact forces destroyed the aircraft. All 12 occupants on board were killed in the accident. The crew consisted of two pilots and ten other military personnel, including aviation maintenance technicians and radio operators.
Findings
The official investigation determined that the accident resulted from a controlled flight into terrain. This outcome was precipitated by the decision to conduct a visual approach in poor weather conditions when instrument approaches were not feasible.