On September 15, 2023, a Cessna 208B Supervan 900 crashed into the Pacific Ocean, approximately 120 km east of Sendai, Japan, resulting in the disappearance of the sole Norwegian pilot, VH-FAY. The aircraft was modified for geophysical survey work and ferried from Jandakot Airport, Australia, to Greenwood, Mississippi, USA. After stopping in Alice Springs, Weipa, and Horn Island, it continued to Guam and Saipan. At Saipan, the pilot detected damage to the propeller anti-ice boot, leading to a delay of more than a week. The aircraft then took off from Saipan, Commonwealth of the Northern Mariana Islands, USA, for a ferry leg to New Chitose, Japan, with an estimated flight time of 9 hours. Approximately 1 hour after takeoff, the aircraft leveled out at flight level FL220. The next report was not received by the Japanese ATC, and two F-4 Japanese Air Self-Defense Force aircraft observed the flight, but were unable to establish radio contact. The pilot was descending rapidly into cloud, and the aircraft disappeared 2 minutes later. The aircraft’s rear passenger door was found, with no other parts located, and the pilot was not identified. The ATSB concluded the pilot was incapacitated and did not recover. Due to fuel starvation, the engine stopped, causing the aircraft to descend uncontrollably into the ocean. The cause of incapacitation was likely due to pilot inaction, exacerbated by an unsuitable oxygen system, increasing the risk of hypoxia.On September 15, 2023, a Cessna 208B Supervan 900 crashed into the Pacific Ocean, approximately 120 km east of Sendai, Japan, resulting in the disappearance of the sole Norwegian pilot, VH-FAY. The aircraft was modified for geophysical survey work and ferried from Jandakot Airport, Australia, to Greenwood, Mississippi, USA. After stopping in Alice Springs, Weipa, and Horn Island, it continued to Guam and Saipan. At Saipan, the pilot detected damage to the propeller anti-ice boot, leading to a delay of more than a week. The aircraft then took off from Saipan, Commonwealth of the Northern Mariana Islands, USA, for a ferry leg to New Chitose, Japan, with an estimated flight time of 9 hours. Approximately 1 hour after takeoff, the aircraft leveled out at flight level FL220. The next report was not received by the Japanese ATC, and two F-4 Japanese Air Self-Defense Force aircraft observed the flight, but were unable to establish radio contact. The pilot was descending rapidly into cloud, and the aircraft disappeared 2 minutes later. The aircraft’s rear passenger door was found, with no other parts located, and the pilot was not identified. The ATSB concluded the pilot was incapacitated and did not recover. Due to fuel starvation, the engine stopped, causing the aircraft to descend uncontrollably into the ocean. The cause of incapacitation was likely due to pilot inaction, exacerbated by an unsuitable oxygen system, increasing the risk of hypoxia.