What happened
On 11 December 2023, at approximately 08:23 local time, an F-16CM, tail number 88-0479, departed Kunsan Air Base, Republic of Korea, for a scheduled defensive counter air (DCA) training mission. The aircraft was part of a four-ship formation assigned to the 80th Fighter Generation Squadron, under the 8th Fighter Wing.
While operating within local training airspace, the flight encountered instrument meteorological conditions (IMC) characterized by dense cloud coverage that exceeded previous forecasts. During this period, the pilot experienced a failure of the embedded global positioning system inertial navigation system (EGI). This malfunction resulted in the loss of the primary attitude indicator.
To maintain situational awareness, the pilot transitioned to using the standby attitude indicator (SAi). However, because the pilot had previously noted pitch and bank discrepancies on this secondary instrument during the flight, reconciling the SAi data with airspeed and altitude became increasingly difficult. While attempting to descend toward expected cloud-free skies, the pilot experienced significant spatial disorientation. As the aircraft approached the water, the pilot elected to eject. The F-16CM subsequently impacted the Yellow Sea, approximately 81 nautical miles west of Kunsan Air Base, and was destroyed. The pilot sustained no injuries.
The investigation
The investigation focused on the sequence of events leading to the loss of the aircraft and the failure of critical flight instrumentation. Investigators examined the functionality of the EGI and its impact on the primary flight displays. The board also reviewed the reliability of the standby attitude indicator and the pilot's ability to maintain control during the transition from primary to secondary instruments under IMC. Notably, the Crash Survivable Memory Unit (CSMU) was unavailable for forensic analysis at the time of the report.