What happened
On the afternoon of 19 June 2021, a pilot operating an Auto-Gyro Cavalon gyrocopter, registration ZU-RBM, was performing a private flight between Morning Star Aerodrome and Stellenbosch Aerodrome. After landing at Stellenbosch and remaining on the ground for a period, the pilot prepared for a return departure from Runway 19.
During the takeoff roll, the pilot attempted to pre-rotate the main rotors to approximately 200 rpm by applying back pressure on the control stick. However, the brakes were released before the control stick had reached the full back position. This caused the aircraft to accelerate at an excessive rate, leading to instability in the nose wheel. The gyrocopter subsequently pitched upward, causing the lower tail plane to strike the ground. The aircraft then rolled to the left and skidded across the grass, with the main rotor blades striking the ground. The event was recorded on a mobile phone.
The investigation
The investigation, conducted by the SACAA AIID based on submitted information, established that the aircraft sustained substantial damage during the excursion. There were 0 fatalities and 0 injuries resulting from the event. The investigation reviewed the sequence of the takeoff roll and the mechanical interaction between the braking system and the control inputs.
Findings
- The primary cause of the accident was the premature release of the brakes before sufficient back pressure had been applied to the control stick.
- This sequence of actions led to an uncontrolled acceleration and a high nose-up attitude.
- The loss of control resulted in the aircraft striking the ground with its tail plane and rotor blades.