What happened
On the morning of 30 April 2023, a Cessna 208B, registration ZS-LEC, was operating a short passenger flight between Madikwe East and Madikwe West Aerodromes. After completing a brief flight segment with seven passengers on board, the pilot-in-command took control of the aircraft to taxi toward a designated parking area on the apron.
During the maneuver, the pilot attempted to use the left brake to execute a left turn, but the braking system failed to respond. Despite attempts to pump the brakes, the aircraft continued its course toward an electric fence. In an effort to slow the aircraft, the pilot applied reverse thrust. As the aircraft approached the perimeter, the pilot attempted a sharp right turn to avoid the obstacle; however, the propeller struck a steel fence post. The impact caused substantial damage to both the propeller blades and the engine.
The investigation
SACAA AIID investigators examined the aircraft's mechanical condition and the aerodrome environment. A follow-up inspection of ZS-LEC revealed no visible leaks, no ruptured hydraulic lines, and a full hydraulic fluid reservoir. No mechanical defects were found in the braking system that could explain the pilot's reported loss of differential braking.
The investigation also assessed the layout of Madikwe West Aerodrome. While the apron provided sufficient space for the aircraft, investigators noted that an electric fence had been erected near the terminal building to create a protected overnight parking area. This area was found to be overgrown with vegetation, suggesting it had not been used recently. Additionally, the steel posts supporting the fence lacked any high-visibility markings, such as bright paint.
Findings
- The primary cause of the incident was the lack of differential braking during the taxi maneuver, which led to an apron excursion.
- The steel fence posts supporting the electric fence were not painted in a bright, visible color.
- The presence of the overnight parking area near the apron created a navigational hazard for maneuvering aircraft.
- There was a lack of signage or information boards warning pilots of the specific hazards or the intended use of the parking area near the fence.