Incident Summary
On the afternoon of 30 November 2022, a student pilot flying a Hughes Helicopters 269C, registered VH-OBK, was returning to Moorabbin after completing the second solo navigation training flight. As the helicopter approached the landing area, the approach became unstable, prompting the pilot to initiate a go-around. Climbing to about 650 ft above ground level, the pilot turned right onto the downwind leg to position for a second approach. Shortly thereafter, the pilot noticed reduced performance and decided to continue the turn back toward the airport. The helicopter continued to lose height, and recognizing the need for a forced landing, the pilot turned left toward a school ground to attempt an autorotation landing. The helicopter subsequently collided with the rooftops of two houses just short of the school ground. The pilot sustained serious injuries, and the helicopter was substantially damaged.
ATSB Findings
The Australian Transport Safety Bureau (ATSB) determined that the engine lost power as the helicopter climbed to about 650 ft above ground level. The reason for the power loss was not identified. The power loss was not immediately recognized by the pilot, which limited opportunities for a safe forced landing. During the forced landing, the helicopter did not have sufficient height to reach the selected landing area and collided with rooftops.
Further investigation revealed that the pilot did not perceive a change in engine sound or vibration, partly due to multiple radio broadcasts at the time. Examination of engine manifold pressure indications showed readings significantly higher than expected, consistent with ambient conditions. The distance traveled during the descent matched that expected for an autorotation, and visual inspection of the engine cooling fan and shroud showed no rotational damage, indicating the engine was not running at the time of impact. No actions that could have caused the power loss were reported, and the helicopter had sufficient fuel on board. No other faults with the engine were indicated, and a detailed examination of the engine and airframe was not performed, limiting the ability to determine the cause of the power loss.
Flight Path Analysis
The engine power loss occurred at low altitude over a densely populated area, presenting a challenging scenario for the inexperienced student pilot. The pilot did not immediately identify the power loss and attempted to return to the airport while troubleshooting the reduced performance. During this time, the helicopter passed two suitable forced landing sites. When the pilot recognized the need for a forced landing, the football oval was likely the closest suitable area, but the pilot did not identify it, possibly because it was obscured by the airframe or instrument panel. The pilot selected the school ground as the landing site, but the helicopter lacked sufficient height to reach it, resulting in the collision with rooftops. Despite this, the pilot maintained control of the helicopter and rotor RPM, enabling an autorotation-style landing into the rooftops that maximized survivability.