What happened
On August 28, 2002, a Robinson R-22 Beta helicopter, registration ZS-RCO, was operating in the Kwandwe Nature Reserve area. The pilot had been conducting game capturing activities throughout the day and intended to relocate the aircraft to a nearby game farm following a refueling stop.
During the refueling process, the pilot assisted initially but then left the task to an assistant. The aircraft was refueled using a 44 US gallon drum. Following the refueling, the pilot agreed to a short, 12-minute pleasure flight requested by an eight-year-old passenger. During the final approach to the landing site, at an altitude of roughly 50 feet and a speed of 20 knots, the engine began to stutter and subsequently failed.
The pilot executed an immediate autorotation to the ground. Upon touchdown, the aircraft skidded forward and struck a cactus bush, which caused the helicopter to roll over. There were no injuries to the two occupants.
The investigation
Investigators examined the refueling procedures and the condition of the fuel used during the operation. It was noted that no fuel sample was taken prior to the flight, as the same drum had been used for refueling earlier that day without issue. The investigation also looked into the logistics of fuel transport and storage during the game capturing mission.
Findings
- The primary cause of the engine failure was contaminated fuel entering the engine's fuel system.
- There was a lack of adequate supervision during the refueling process.
- No testing or sampling of the fuel for grade or contamination was performed before the flight.
- Fuel storage and handling practices were insufficient, as fuel was being transported in drums on the back of a light delivery vehicle or truck. The drums were left upright in various weather conditions, including rain, and overnight, which facilitated condensation and subsequent contamination.