What happened
On 8 March 2015, a Garlick UH-1H helicopter, registration ZS-HBV, crashed in an open field within the Cape Point National Park. The aircraft was part of a three-helicopter formation deployed from Newlands Forest Station to assist in suppressing a wildfire. The mission involved using Bambi buckets to transport water from nearby sources to the fire site.
During the flight, the pilot reported a transmission chip warning light in the cockpit. While the pilot intended to continue to a support vehicle for inspection, the aircraft suddenly entered an uncontrollable state. Other pilots in the formation observed the helicopter spinning wildly and gyrating at approximately 8/00 feet AGL. During the descent, the attached Bambi bucket swung upward, striking the main rotor blades. The helicopter impacted the terrain in a nose-down attitude and was consumed by a post-crash fire. The pilot, the sole occupant, sustained fatal injuries.
The investigation
SACAA AIID investigators examined the wreckage and interviewed witnesses, including the other pilots involved in the firefighting mission. The investigation focused on the sequence of events following the pilot's report of a chip light. Investigators analyzed the condition of the tail rotor gearboxes and the control cables to determine why the aircraft lost directional stability. The inquiry also reviewed the pilot's flight experience and the maintenance history of the aircraft.
Findings
- The primary cause of the accident was the pilot's inability to maintain control of the aircraft following a loss of tail rotor thrust.
- This loss of thrust was triggered by the fracture of the left-hand aft control cable during flight.
- The failure of the tail rotor driveshaft followed the initial cable fracture.
- The impact of the Bambi bucket with the main rotor blades contributed to the rapid descent and subsequent impact.