What happened
On May 12, 2014, a privately owned Extra EA3-00/L, registration JA111L, departed from Fukushima Sky Park Temporary Air Field for a planned aerobatic session. The flight involved two occupants: the captain, seated in the rear, and a pilot, seated in the front. During the flight, the crew performed multiple sequences of acrobatic maneuvers, including inverted flight, at altitudes ranging from 1,500 to 4,500 feet.
After completing the third sequence of the day, the aircraft began its descent toward the airfield. As the aircraft approached the downwind leg of the runway at approximately 1,200 feet, the captain took control of the aircraft. Upon attempting to increase engine power to maintain level flight, the engine failed to respond to throttle adjustments. Realizing the aircraft could not reach the airfield, the captain declared an emergency and executed a forced landing into a peach orchard in the mountain area.
During the descent, the aircraft's left wing struck an iron pole located at the edge of the orchard. The aircraft subsequently landed upside down in a bamboo grass field. The impact resulted in one serious injury and one slight injury. The aircraft sustained extensive damage, including the separation of the left wing, engine detachment, and propeller failure, ultimately resulting in the destruction of the airframe.
The investigation
The Japan Transport Safety Board (JTSB) examined the aircraft's mechanical condition, the crew's flight planning, and the fuel management practices. Investigators inspected the engine, fuel pump, fuel injector, and spark plugs, finding no mechanical anomalies. Post-accident analysis of the fuel tanks revealed that the center tank was empty and only a negligible amount of fuel remained in the acro tank.
Investigators also reviewed the crew's preflight briefing and endurance calculations. The captain had estimated a flight endurance of approximately 33 minutes, while the pilot estimated 35 minutes. The investigation focused on why the actual fuel consumption exceeded these estimates and why the crew did not identify the approaching fuel exhaustion during the flight.