What happened
On July 6, 2022, at approximately 15:23 local time, a commercial helicopter pilot was performing a translational flight within a confined area at the Antillanca Ski Center in the Los Lagos Region, Chile. The pilot was attempting to reposition the AW119 MKII to a more suitable location for passenger boarding, as the original spot was covered in approximately 1.5 meters of soft snow.
While hovering at an altitude of two to three meters, the pilot initiated a right-hand turn. During this maneuver, the aircraft's tail rotor blades struck tree branches located near the movement area. The impact caused immediate damage to both tail rotor blades and induced a rapid rightward yaw. Following established emergency procedures, the pilot reduced power to idle and used the collective to perform a controlled touchdown on the snowy terrain. The pilot was able to exit the aircraft safely, and no injuries were reported.
The investigation
DGAC Chile examined the aircraft, the site, and the operational circumstances. The investigation confirmed that the pilot held a valid commercial license and that the aircraft's maintenance records were up to date, with the most recent inspection completed shortly before the event. The investigation also noted that the engine was subject to inspection due to the abrupt shutdown following the tail rotor impact.
Investigators reviewed the environmental conditions, noting that while the area was experiencing cloudy skies and significant winds, visibility was not compromised by whiteout conditions or blowing snow. The investigation also looked into the operational procedures of the operator, specifically regarding ground support during maneuvers in restricted spaces. \n## Findings
- The primary cause of the accident was the impact of the tail rotor blades against tree branches during a translational flight in a confined area.
- The pilot failed to maintain a safe distance between the tail rotor and nearby obstacles.
- A lack of depth perception regarding the surrounding environment prevented an accurate assessment of the safety clearance required for the right-hand turn.
- The operator's manual did not require ground personnel to assist with guiding the pilot during movements in confined areas; notably, a maintenance mechanic was present nearby but was not utilized as a ground guide.
- The damage to the tail rotor blades directly caused the loss of directional control, necessitating the emergency landing.