What happened
On 21 April 2024, a Jabiru J430 with registration ZU-MJM was preparing for a recreational flight from Nandoni Private Airstrip in Limpopo to Polokwane Civil Aerodrome. The aircraft was carrying a pilot and three passengers under clear weather conditions.
During the take-off roll on Runway 14, the pilot applied full power and began accelerating. However, the pilot observed that the indicated airspeed remained at zero. In response, the pilot immediately closed the throttle and applied the brakes. By this point, the aircraft had already traversed nearly half of the available runway. Because the remaining runway surface sloped downward, the pilot found it difficult to decelerate the aircraft within the remaining distance. To mitigate the impact, the pilot steered the aircraft toward the right, exiting the runway into a nearby wetland. The aircraft sustained substantial damage, specifically to the propeller blades, the right main gear strut, and the right-wing tip. There were no injuries to the occupants.
The investigation
An investigation by the SACAA AIID established that the aircraft's pitot-static system was compromised. Following the accident, it was discovered that an insect had become lodged inside the pitot tube. This blockage prevented the ram air from reaching the airspeed indicator, resulting in the zero-speed reading during the acceleration phase. The investigation also noted that while the aircraft was within its maintenance intervals, the available runway length was insufficient for a safe stop once the abort was initiated, as the aircraft required approximately 750 meters to stop, while only 600 meters of runway remained.
Findings
- The primary cause of the aborted take-off was a bug lodged in the pitot tube, which caused the airspeed indicator to fail to show increasing speed.
- The pilot was unable to stop the aircraft safely on the remaining runway due to the insufficient distance and the downward slope of the runway surface.
- A contributing factor to the incident was an inadequate or non-existent pre-flight inspection regarding the pitot tube.