Flight History
The Cessna 208B aircraft, registered VH-FAY, departed Jandakot Airport, Western Australia on 15 September 2018, bound for the United States via the North Pacific Route. After an overnight stop in Alice Springs to repair a standby alternator fault, the pilot flew to Weipa, Queensland, then to Horn Island. On 17 September, the aircraft departed Horn Island for Guam but instead landed at Saipan, Northern Mariana Islands. A damaged propeller anti-ice boot delayed departure until 26 September.
Last Communications
On 26 September at 2300 UTC, the aircraft departed Saipan for New Chitose Airport, Japan. The pilot reported clear weather, flight level 220, a tailwind, and fuel flow of 288 lb/hr. At 0121 UTC, the pilot contacted Tokyo Radio over HF, estimating arrival at reporting point SAGOP at 0244. GPS data showed the aircraft passed SAGOP at 0241, but no further communication was received. Tokyo Radio made repeated attempts to contact the pilot without success.
Intercept and Loss
About 4.5 hours after the last communication, two Japan Air Self-Defense Force (JASDF) aircraft intercepted VH-FAY. The pilot did not respond according to international intercept protocols, and the aircraft continued on its planned track at FL 220. The JASDF pilots could not see into the cockpit to assess the pilot's condition. After about 30 minutes, the aircraft descended into cloud. At 0626 UTC, the GPS tracker ceased reporting at FL 220, approximately 100 km off the Japanese coast. Radar data indicated a rapid descent, and the aircraft collided with water about two minutes later.
Search and Recovery
Japanese authorities launched a search within two hours; the aircraft's rear passenger door was found. A typhoon suspended search for two days. The search continued until 27 October, but no further wreckage or the pilot was located.
Investigation Findings
The investigation determined that during the cruise between Saipan and New Chitose, the pilot very likely became incapacitated and could no longer operate the aircraft. The engine most likely stopped due to fuel starvation from pilot inaction, resulting in an uncontrolled descent into the ocean. The pilot was operating alone in the unpressurised aircraft at 22,000 ft and probably not using the oxygen system appropriately, which increased the risk of hypoxia.