What happened
On 06 February 2014, a Cessna A188B engaged in a commercial crop spraying operation departed from Joubertina aerodrome in the Eastern Cape. The pilot, the sole occupant of the aircraft, had loaded 600 litres of chemical into the hopper and 37 gallons of Avgas LL 100 for the mission. After completing several successful spraying passes over a nearby field, the aircraft attempted a 180-degree turn at approximately 300 feet above ground level near a mountain site.
During this maneuver, the aircraft was unable to maintain its flying speed and began a steady descent. In an effort to recover, the pilot immediately jettisoned approximately 460 litres of the remaining chemical to reduce weight. Despite this action, the aircraft continued to lose altitude, eventually striking tall trees. The impact caused the aircraft to nose over in a bushy area, resulting in the total destruction of the Cessna A188B. The pilot sustained minor injuries but survived the impact.
The investigation
An investigation by the SACAA AIID examined the wreckage, the pilot's credentials, and meteorological conditions. Technical inspections of the aircraft revealed no mechanical anomalies or engine failures prior to the impact. The aircraft was within its allowable weight limits at takeoff, and the fuel was found to be free of contamination. Data retrieved from the aircraft's AG-Nav Guia GPS confirmed the flight path and showed a decrease in airspeed and abrupt deviations immediately preceding the crash.
Investigators also reviewed the pilot's records, noting that while the pilot held a valid commercial license and was rated on the aircraft type, he did not possess a specific rating for agricultural operations. Additionally, the investigation identified that the aircraft's Certificate of Airworthiness had expired in September 2013.
Findings
- The primary cause of the accident was the failure to maintain flying speed during the turn.
- The aircraft encountered mountain wave turbulence on the lee side of the mountain, which significantly impacted the aircraft's airspeed and altitude.
- The pilot's inability to recognize the hazards associated with mountain flying contributed to the loss of control.
- The aircraft was operating with an expired Certificate of Airworthiness.