What happened
On 21 November 2017, a Trojan Gyrocopter, registration ZU-RKJ, was conducting a test flight near Parys, South Africa. The pilot had departed from Klipdrift farm with the intention of overflying Parys Airfield before returning to the same location. The primary purpose of the flight was to evaluate the performance of newly installed software for an agricultural crop-spraying system.
During the flight, the aircraft experienced a sudden loss of power. This loss of engine performance caused the aircraft to lose forward airspeed, leading to a nose-first impact with the ground. Following the initial impact, the aircraft rolled onto its right side, causing the rotor blades to strike the earth. A significant post-impact fire erupted, consuming the wreckage and the surrounding vegetation. Farm workers nearby, who had noticed a veld fire, discovered the burning aircraft and found the pilot approximately 3 metres from the wreckage. The pilot sustained fatal injuries.
The investigation
SACAA AIID investigators examined the wreckage and conducted a teardown inspection of the Subaru engine. While the engine components showed no obvious signs of mechanical failure or bearing issues prior to the impact, the investigation noted that the engine was not running at the moment of impact, as evidenced by the intact condition of two propeller blades.
Investigators also reviewed the aircraft's maintenance history and fuel records. The aircraft had been recently refuelled and possessed sufficient fuel for the 15-minute flight duration. The investigation also noted that while the pilot held a valid National Pilot Licence, they did not possess the specific test pilot rating required for conducting flights involving major modifications, such as the recently installed crop-spraying system.
Findings
- The primary cause of the accident was an engine failure, which resulted in a loss of airspeed and the subsequent ground impact.
- The specific reason for the engine failure could not be determined due to extensive fire damage to the engine's electrical and ignition components.
- The aircraft was equipped with a crop-spraying hopper containing Molopo granules, which contributed to the intensity of the post-impact fire.
- The pilot was performing a test flight for a major modification without the required test pilot rating.