What happened
On 27 March 2017, a Robinson R22 helicopter, registration ZK-IHA, was engaged in an aerial hunting mission near Reefton when it struck a tree canopy and subsequently crashed into the terrain. The aircraft was transporting a slung load consisting of two animal carcasses at the time of the accident. Shortly after departing from a skid site to return to its home base, the helicopter entered a descent through thick forest, leading to the destruction of the aircraft and the fatal injury of the pilot.
The investigation
Investigators examined the wreckage and recovered GPS data to reconstruct the flight path. Analysis of the engine and components revealed that the engine was likely unable to produce its maximum rated power. Furthermore, evidence from the cockpit indicated that the 'Low Rotor RPM' warning light was active at the moment of impact. /nTechnical inspections of the aircraft uncovered significant maintenance discrepancies. The helicopter's airworthiness review had expired ten days prior to the crash, and the engine showed signs of wear that did not align with the hours recorded in its logbook. Additionally, investigators found that the aircraft's hour meter had been disabled, and the total time in service was higher than officially documented. The investigation also noted that the pilot was performing commercial duties that exceeded the privileges of a private pilot licence.
Findings
- A low rotor-revolutions-per-minute event likely occurred during the accident sequence.
- The engine was in a condition that would have prevented it from delivering maximum specified power.
- The helicopter was operated over high-risk, densely forested terrain despite safer takeoff alternatives being available.
- Maintenance practices were inconsistent with manufacturer instructions and Civil Aviation Rules, specifically regarding engine wear and logbook accuracy.
- The pilot conducted commercial flight operations without the appropriate licence privileges.
Safety action
While no new recommendations were issued by the Commission, the investigation highlighted the importance of the Aviation Related Concerns system. It was noted that industry participants had previously held concerns regarding the pilot's compliance but had not reported them due to fears of reputational impact within the small aviation community.