Preliminary Investigation of a Bell 412 Helicopter Accident in Coelemu, Chile

Incident Overview and Location On March 11, 2022, at 17:30 local time, a Bell 412 helicopter operated by a commercial helicopter pilot made a precautionary landing in the rural sector of Coelemu, Ñuble Region, Chile. The incident occurred during a wildfire-fighting flight after the helicopter had refueled with water from a local reservoir. The pilot reported experiencing vertical vibrations, prompting the decision to land. The pilot was uninjured, while the aircraft sustained damage. ## Aircraft and Pilot Information The aircraft was a Bell 412 helicopter, serial number 33084, manufactured in 1982, with 15,653.1 flight hours at the time of the incident. It was powered by two Pratt & Whitney Canada PT6T-3B series engines. The pilot was a 56-year-old Chilean national holding a commercial helicopter pilot license with type ratings for the Bell 412 and other helicopter models. The pilot had a total of 7,964.18 flight hours, including 2,985.00 hours on the Bell 412. ## Damage and Maintenance Status The helicopter sustained damage to its nose, including fractures and deformation in the lower section, multiple fractures in the radar protection cowl, and destruction of the right windshield and lower windows. The landing skids were deformed, opened, and tilted backward, with fractured rear fittings. The main drive shaft showed evidence of displacement and impact at its front coupling. The aircraft's maintenance records indicated compliance with the approved maintenance program, with the last 600-hour inspection completed on September 13, 2021. The helicopter had been de-preserved and returned to service in November 2021. ## Site and Operational Context The accident site was located on a flat, hard surface covered with dry grass, belonging to a timber company. An artificial lagoon was present, used by helicopters for water refueling during wildfire suppression. The helicopter was found 263 meters from the water refueling point, oriented on a heading of 150°, in the takeoff path. No impact with obstacles was observed. The Bambi Bucket used for water delivery was undamaged. The aircraft's total weight at the time of the incident was estimated at 10,821.06 pounds, within its maximum permissible weight of 11,200 pounds. Meteorological conditions were suitable for visual flight rules (VFR) operations.