What happened
On 05 April 2018, a student pilot was conducting a training flight involving rapid deceleration maneuvers, commonly known as "quick stops," at Virginia Airport in KwaZulu-Natal. During the final phase of a maneuver, as the pilot attempted to level off, the aircraft's low RPM warning horn activated, signaling a significant drop in rotor speed. This triggered a sudden loss of altitude.
In an attempt to arrest the descent, the pilot increased collective pitch. However, the Robinson R22 Beta, registration ZS-RGJ, struck the ground with significant force. The impact caused the aircraft to lift off momentarily on the right skid and pivot around the left skid. The pilot managed to stabilize the aircraft by applying appropriate cyclic and pedal inputs and eventually lowered the collective to settle the helicopter back on the ground. There were no injuries to the pilot, though the aircraft sustained damage to the lower fuselage and the tail cone root.
The investigation
SACAA AIID investigators examined the flight circumstances and the aircraft's maintenance history. The investigation confirmed that the pilot held a valid student pilot license and a current medical certificate. The aircraft, ZS-RGJ, was properly documented with a valid Certificate of Airworthiness and Certificate of Registration. Maintenance records showed that the helicopter had undergone its last mandatory periodic inspection approximately seven months prior to the event, with only 93.4 airframe hours flown since that inspection.
Findings
- The primary cause of the hard landing was a loss of rotor RPM.
- This loss of rotor speed was directly attributed to the pilot providing insufficient collective input during the recovery phase of the quick stop maneuver.