Synopsis
On 4 May 2018, at approximately 1515Z, a Schweizer 269C helicopter registered ZS-RBJ departed from a farm in the Bultfontein district of the Free State province for a private game-viewing flight. The helicopter carried one pilot and one passenger. Shortly after take-off, while climbing through about 100 feet above ground level, the engine stopped operating. The pilot executed a forced landing onto open flat terrain. The helicopter impacted heavily and sustained substantial damage. Neither occupant was injured.
Flight History
The pilot reported performing a pre-flight inspection and refueling with approximately 40 litres of Avgas LL100 from a 53 US gallon drum. After startup and checks, the helicopter lifted into hover and transitioned to forward flight. As it ascended through 100 ft AGL, a sudden change in engine noise occurred, followed by engine stoppage. The pilot initiated a forced landing; the helicopter impacted the ground hard and sustained extensive damage. The accident occurred in daylight at coordinates 28°16’46.3” South 025°52’46.00” East, elevation 4360 ft AMSL.
Investigation Findings
Examination of the wreckage revealed water in the fuel lines when the engine was disconnected and removed from the airframe. The engine itself showed no evidence of mechanical malfunction. The pilot had sourced fuel from drums obtained from different service providers. The pre-flight inspection instructions in the Pilot's Operating Handbook require checking the fuel sump and strainer for water or contamination. An official weather report indicated surface wind 025°/5 kt, temperature 22°C, dew point 6°C, visibility 10 km CAVOK, with no bearing on the accident. The helicopter was privately owned and operated under Part 91 of the South African Civil Aviation Regulations. The pilot held a valid private pilot licence and medical certificate.
Probable Cause
The investigation determined that the accident resulted from an unsuccessful forced landing following an engine stoppage after take-off, which was attributed to fuel contamination.
Contributing Factors
A contributing factor was an improper pre-flight inspection by the pilot. According to the report, if he had drained the fuel tanks prior to the flight, it would have been highly probable that he would have found water in the fuel.