Accident Summary
On 6 May 2023, at approximately 09:27 a.m. Korea Standard Time, an F-16C Fighting Falcon, tail number 88-0549, assigned to the 80th Fighter Squadron, 8th Fighter Wing, Kunsan Air Base, South Korea, took off as part of a routine training sortie during exercise BEVERLY HERD. The mishap pilot (MP) was flying as the second aircraft in a 4-ship formation. Two minutes and forty-one seconds after takeoff, the MP ejected with minor injuries. The aircraft was destroyed upon impact in an agricultural field approximately 8 nautical miles south of Osan Air Base at about 09:30 a.m. The loss was valued at $29,387,925.
Sequence of Events
The weather at the airfield and surrounding area featured clouds obscuring the horizon from 1,400 feet up to 17,000 feet. Approximately 11 seconds after takeoff, while in clouds, the aircraft experienced a partial electrical power loss. This caused the primary flight instruments to display inaccurate horizon information without any failure indications. The MP was unable to determine the horizon's location. The degradation and mismatch between the primary and standby horizon indicators led to spatial disorientation. The MP inadvertently descended to 720 feet mean sea level, at which point recovery was impossible. The pilot ejected at 710 feet above ground level.
Investigation Findings
The Accident Investigation Board President determined, by a preponderance of evidence, that the mishap resulted from two factors. First, the partial electrical power loss caused a cascading failure of primary flight and navigation instruments. The primary horizon direction indicator continued responding to pilot inputs but displayed unreliable data without warnings, impeding the pilot's transition to the standby indicator. Second, the weather conditions forced the MP to rely solely on flight instruments during a critical phase of flight. The data mismatch between the primary and standby attitude indicators, due to the power disruption, caused spatial disorientation and loss of aircraft control at low altitude. The board noted that the absence of either factor might have prevented the accident.
Aircraft and Pilot Information
The F-16C (T/N 88-0549) was assigned to the 80th Fighter Squadron. The MP was appropriately qualified and on a planned training mission. The aircraft's crash survivable flight data recorder and digital flight control system data were analyzed. The electrical system suffered an anomaly, and no other significant maintenance issues were identified. The pilot's toxicology tests were negative, and crew rest was adequate.
Conclusion
The accident was caused by the combination of a partial electrical power loss and weather conditions, leading to spatial disorientation and loss of control. The pilot ejected successfully and sustained minor injuries.