What happened
On September 12, 2016, a Eurocopter AS350-B2 helicopter, registration ZK-HYY, was conducting a scenic flight for five passengers near Queenstown, New Zealand. Originally destined for Mount Vanguard, the pilot diverted the flight to Mount Sale due to deteriorating weather conditions.
As the aircraft approached the landing site at approximately 1,500 metres, the pilot attempted a landing from the north. During the final stage of the approach, the helicopter experienced a sudden, significant increase in the rate of descent. In an attempt to recover, the pilot applied maximum power to perform a go-around. However, the aircraft's right skid struck the ground at roughly 20 knots, causing the helicopter to bounce and eventually roll onto its side. One passenger sustained a minor knee injury, while the aircraft suffered substantial damage.
The investigation
Investigators from the TAIC examined the wreckage and the aircraft's maintenance history. The technical inspection of the engine and flight controls revealed no mechanical failures or performance limitations; the engine was delivering high power, and the aircraft was operating within weight and balance limits.
The investigation also reviewed the pilot's training and recent flight history. The pilot was experienced, with over 2,700 total flight hours, and had recently completed competency checks. However, investigators noted that the operator had experienced four serious landing accidents within a three-year period, though the specific causes for those previous events remained inconclusive.
Findings
- The pilot performed the final approach with a tailwind, despite expecting a crosswind.
- The approach was executed at a high speed, low, and close to the landing site, which prevented the pilot from having sufficient time to verify actual wind conditions.
- The sudden sink likely occurred because the airspeed dropped below the threshold for translational lift while the ground speed remained high.
- The tight, low-altitude turn used during the approach effectively blocked the pilot's intended escape route, making a successful go-around impossible once the sink began.
- The failure of the emergency locator transmitter (ELT) antenna during the impact highlighted a potential risk to search and rescue efforts.
Safety action
Following the inquiry, the operator implemented human factors training for operational personnel. Additionally, the Commission recommended that the operator review its safety management system (SMS) audit processes to ensure robust risk management and safety assurance. The Civil Aviation Authority also noted that helicopter operational culture remains a factor in the sector's risk profile.