What happened
On 13 January 2023, an Ayres S2R-T15 aircraft, registered ZS-PNC, was performing aerial work in the Mpumalanga province. While the pilot was engaged in spraying fungicide on a private farm in Jantjieshoek, the aircraft experienced a sudden loss of power during a right-hand turn at approximately 700 feet AGL. The pilot noted a drop in inter-turbine temperature and a change in the engine's acoustic profile.
In response to the engine failure, the pilot prepared for a forced landing by leveling the aircraft, configuring it for descent, and feathering the propeller to maximize gliding distance. The aircraft touched down on uneven ground, striking a fence and rolling over a ditch. During the subsequent bounce, the main landing gear collapsed, causing the propeller blades to strike the earth. While the pilot escaped without injury, the aircraft suffered substantial damage to the propeller and undercarriage.
The investigation
SACAA AIID investigators examined the aircraft's maintenance history and engine condition. The aircraft had undergone a mandatory periodic inspection roughly one month prior to the accident, with no major defects noted at that time.
Technical analysis of the engine via borescope inspection revealed several points of interest. Investigators found evidence of potential in-service contamination on the suction side of the blades. Additionally, blue discoloration was noted on the compressor turbine blades, the vane ring, and the exit duct, alongside slight burning and cracking on a small exit duct. The engine has been sent to the manufacturer for a more comprehensive evaluation.