Event Overview
On 12 January 2025, a pilot and ground crew using an Airbus AS350 B3 helicopter, registered ZK-ITY, were tasked to collect two climbers from Turners Bivouac on Mt Madeline, approximately 7 km east of Milford Sound. The landing site was a plateau at 4900 ft altitude. During the approach, the pilot reduced power to settle the helicopter on the skids, but a rock under the rear right skid broke, causing the tail rotor to drop and strike a boulder. The pilot attempted to reposition the helicopter to a safe area, but during the manoeuvre the main rotor struck a large boulder outcrop, causing severe vibration. The pilot shut down the engine, and the helicopter came to rest. The pilot, ground crew, and two climbers were uninjured. Another helicopter recovered all four individuals to Milford Sound.
Landing Site and Conditions
The landing site had been built up with rocks over previous years to create a flat area for helicopters. It was a confined space requiring caution. The pilot landed further to the rear than previous landings, where a rock under the right skid broke under the helicopter's weight. The site consisted of tussock grass and rocks. A broken rock measuring 0.5 m by 0.4 m by 0.15 m was found at the rear right skid position. Scrape marks were found on a boulder approximately 6 m from the landing site, corresponding to tail rotor contact, and on a large boulder outcrop to the right, corresponding to main rotor strike. Weather was fine and clear with little or no wind.
Aircraft and Personnel
The helicopter, serial number 4949, manufactured in 2010, was fitted with a single Safran Arriel 2B1 turboshaft engine. It had a 7-place configuration. Maintenance records were current, with no defects relevant to the accident. The pilot held a Commercial Pilot Licence (Helicopter) with 5300 total hours, including 907 hours on the AS350 type. The pilot had been on duty for 7 hours and reported being fit to fly. The ground crew was another pilot from the same operator.
Sequence of Events
The climbing party had been flown to the site on 11 January 2025 by the operator's lead pilot using a Robinson R44. On 12 January, the mountain guide requested early pickup. The pilot tasked for the flight had not previously landed at this site and discussed the approach with the lead pilot. They decided to bring a ground crew to assist with loading while the pilot remained at the controls. After a scenic flight, the pilot and ground crew departed Lone Tree at 1641 with 35% fuel. They arrived at Turners Bivouac after seven minutes. The pilot circled to locate the climbers and landing site. The approach was direct into the site to minimize downwash. Using nose-mounted mirrors, the pilot positioned the skids over the rough ground. As power was reduced, the helicopter lurched, pitching up and turning left. The pilot re-established a hover, but the main rotor struck an outcrop, causing violent shaking. The helicopter was landed again, turning further left, and the engine was shut down at 1654. The ground crew checked on the climbers; all were uninjured. The operator dispatched a recovery helicopter, which landed near the site at 1758 and transported the climbers and crew to Milford Sound.
Investigation Findings
The investigation examined the site, helicopter, and records. No mechanical defects were found. The weight and balance were within limits. The pilot's decision not to fly away after the tail rotor strike was appropriate, as continued flight would likely have led to inflight breakup. The main rotor strike occurred during the repositioning attempt.