What happened
On 11 January 2024, a Piper PA28-140 with registration ZS-EOZ was conducting flight training maneuvers near Wonderboom Aerodrome. The flight, involving a student pilot and an instructor, was performing simulated engine failure exercises within the General Flying Area 1.
After successfully completing two simulations, the crew initiated a third exercise. During the go-around and initial climb phase of this third attempt, the aircraft failed to gain altitude. The instructor noted that there were no warning indications on the instrument panel as the engine lost power. The instructor subsequently took control of the aircraft and performed a forced landing in a sugar bean plantation. During the landing roll, the aircraft's vertical stabilizer strobe light struck an irrigation spray boom. There were no injuries reported, though the aircraft sustained minor damage.
The investigation
SACAA AIID examined the mechanical and environmental conditions surrounding the event. Post-incident inspections revealed that the engine was capable of operating normally, with all parameters within green arcs once restarted. The investigation also reviewed the meteorological data for the time of the flight, noting a temperature of 25°C and a dew point of 17°C.
Findings
The investigation established that the loss of engine power was probably caused by carburetor icing. While the aircraft was descending at a reduced power setting, the atmospheric conditions—specifically the 8°C dew point depression—placed the engine at a high risk for icing. When the pilot advanced the power lever to transition into the climb, the accumulated ice likely restricted airflow through the venturi, preventing the engine from producing necessary power.