What happened
On the afternoon of August 15, 2015, an experimental ISHIJIMA MCR-01, registration JX0145, departed from the Akeno Sky Sport Club temporary airfield in Chikusei City, Ibaraki Prefecture. The aircraft was carrying a pilot and one passenger. During the flight, witnesses observed the aircraft flying at a low altitude. At approximately 15:49, the aircraft pitched upward, followed by a sudden nose-down attitude. The aircraft then entered a spin, completing several small circles before impacting a golf course in Tsukually City. The impact was severe, resulting in two fatalities. The aircraft was destroyed upon impact, though no post-crash fire was reported.
The investigation
Investigators from the JTSB examined the wreckage and analyzed the aircraft's weight and balance configuration. The investigation focused on the aircraft's stability, the condition of the elevator trim, and the legality of the flight. Key technical details revealed that the aircraft, a modified version of a French-designed model, lacked a specific flight manual or documented weight and center of gravity (CG) limits. The investigation also looked into the mechanical state of the engine, the functionality of the emergency parachute system, and the regulatory permissions held by the pilot for this specific flight.
Findings
- The aircraft's center of gravity (CG) was likely outside the controllable range, positioned too far toward the rear. This instability was exacerbated as fuel was consumed during flight, causing the CG to shift even further aft.
- The aircraft experienced a stall and subsequent spin that the pilot was unable to recover from because the control surfaces had reached their physical limits.
- The elevator trim may have contributed to the accident, as the trim actuator was found in the extreme nose-up position after the crash.
- The flight was conducted without the necessary permissions required under the Civil Aeronautics Act for experimental aircraft operations.
- The aircraft had known maintenance concerns, including a fuel leak and concerns regarding the uniform thickness and strength of the composite fuselage.