What happened
On 19 August 2013, a private hire-and-fly flight departed from Fisantekraal Airfield in the Western Cape. The pilot, accompanied by one passenger, was attempting to take off from Runway 23 in a Magni M16 Gyro, registration ZU-CVH.
During the pre-rotation phase, the pilot increased the rotor RPM to 170 RPM before initiating the forward roll. While attempting to accelerate, the pilot noted that the manifold pressure reached 35 inches, but the rotor RPM failed to reach the target of 190 RPM. Shortly after the takeoff roll began, the pilot experienced violent lateral movement through the cyclic control. In an attempt to stabilize the aircraft, the pilot reduced power to idle, but the gyroplane flipped onto its left side. The aircraft slid approximately 120 meters down the runway, coming to rest at the intersection of runways 05 and 32. The impact caused the fuel tank to rupture, though no fire occurred. The pilot sustained minor injuries to the arm, while the passenger was uninjured.
The investigation
SACAA AIID investigators examined the aircraft, the pilot's credentials, and the airfield environment. The investigation confirmed that the Magni M16 Gyro was airworthy and had been maintained according to regulations. The pilot held a valid Recreational Pilot’s Licence with 70.5 total flying hours.
Investigators also assessed the condition of Fisantekraal Airfield, noting that the runway infrastructure and maintenance did not meet regulatory requirements. The investigation focused on the aerodynamic phenomenon of blade flapping, which occurs when excessive airflow passes through a rotor system operating at low RPM.
Findings
- The primary cause of the accident was incorrect technique employed during take-off.
- The pilot applied full power before the rotor RPM had reached a sufficient level.
- This lack of sufficient RPM relative to the forward airspeed caused rotor blade flapping, leading to a total loss of control.
- The aircraft sustained substantial damage, including a ruptured fuel tank and a detached wheel.
- The accident was considered survivable due to the low impact forces and the use of safety harnesses and helmets by both occupants.
Safety action
- A recommendation was made to the Director of Civil Aviation to conduct a full audit of Fisantekraal Aerodrome to ensure the facility complies with Civil Aviation Regulations.