What happened
On the morning of 11 October 2025, a training flight departing from Ultimate Heliport in Midrand, Gauteng, resulted in a serious incident. The flight, conducted under Part 141 regulations, involved a flight instructor and a student pilot operating a Robinson R44 Raven II, registration ZS-RMN. The intended destination was Grand Central Airport.
Following a standard pre-flight inspection and engine start, the student pilot increased the throttle to 104 percent RPM and commenced takeoff. As the aircraft climbed to approximately 150 metres above the ground, the rotor RPM warning light and audio alarm activated, signaling a significant decay in rotor speed. The aircraft lost altitude rapidly. The flight instructor immediately took control and attempted an emergency landing. While the instructor managed to flare the aircraft, the helicopter struck a grass area approximately 1 kilometre east of the Ultimate Heliport facility with significant force. There were no injuries to the occupants, though the landing caused minor damage to the skid landing gear.
The investigation
SACAA AIID investigators examined the aircraft and the flight parameters. The investigation confirmed that the aircraft was airworthy and maintained in accordance with approved procedures, with all mandatory inspections and service bulletins up to date. A post-accident examination of the Robinson R44 Raven II did not reveal any mechanical failures; the engine governor, cylinder compression, and tail rotor components were all found to be in serviceable condition. The investigation focused on the flight dynamics and the sequence of events leading to the RPM decay.
Findings
- The primary cause of the incident was an unsuccessful emergency landing following a decay in main rotor RPM during low-level flight.
- A contributing factor to the event was poor airmanship during the flight maneuvers.