Incident Overview
On the morning of 18 October 2021, a Robinson R44 Raven II helicopter, registration ZS-PWH, was involved in a serious incident during a private flight in the Western Cape Province, South Africa. The flight departed from Botlierskop Game Reserve and was intended to return there. No flight plan was filed, and visual meteorological conditions (VMC) by day prevailed at the time.
Aircraft and Flight Details
The helicopter, serial number 11760, was owned by the game reserve owner and was normally parked at the reserve's helipad. The pilot held a valid Private Pilot Licence with a helicopter type endorsement and had 630.8 total flying hours, including 7.2 hours on type. Onboard were the pilot and two passengers. The helicopter had approximately 60 litres of Avgas LL100 fuel in the tank.
Sequence of Events
The pilot conducted a pre-flight inspection with no abnormalities found, provided a pre-flight briefing to passengers, and ensured they were properly harnessed. After starting the engine and confirming all indications were within the green arch, the helicopter lifted off uneventfully, climbing to 500 feet AGL at 70 KIAS, heading southwest toward the Boggomsbaai area. En route, the pilot heard a loud bang and felt a vibration on the controls, though engine indications remained within limits. The pilot decided to execute a precautionary landing on a beach. During landing, the pilot flared the helicopter too high, causing the main rotor to diverge. The number 1 main rotor blade (Part No. C016-7, Serial No. 11818) struck the top of the tail boom's monocoque shell, damaging it. The tail boom shaft remained intact. After settling, the pilot shut down the engine and electrical systems. The helicopter sustained minor damage; no injuries were reported.
Post-incident Examination
A walk-around inspection revealed evidence of a bird strike: blood stains on the lower section of the number 2 main rotor blade (Serial No. 11824, Station No. 174), near the blade tip. The bird was not found, so its species could not be determined. Inspection of the blades showed no damage to the spars, skin-to-spar joints, or aerofoil areas; the blade set was not replaced. Examination of the pilot's file confirmed he was correctly licensed and fit for the flight. The helicopter's maintenance records showed no abnormalities or defects, and no open or differed maintenance items were noted before the flight.
Probable Cause
The probable cause of the incident was that the precautionary landing was carried out after a loud bang and vibration due to a bird strike, resulting in the tail boom being struck by the number 1 main rotor blade. A contributing factor was that the pilot flared the helicopter too high during the precautionary landing.