What happened
NTSB summary, verbatimThe Title 14, CFR part 135 helicopter air tour flight was entering a mountainous crater. A passenger's videotape showed that the flight was initially performed in visual meteorological conditions, but as the helicopter approached the crater's 5,000-foot msl rim, its proximity to the clouds decreased, and the videotape ended. The videotape showed that the clouds were both above and below the helicopter. Recorded radar data, which ended about the time of the crash, showed that during the final few seconds of flight, the pilot maneuvered over the area, and its ground speed decreased from about 100 to 5 knots. Within the last 14 seconds of flight a descent was initiated, which increased in vertical speed to 2,000 feet per minute. The helicopter collided with the interior wall of the crater, and tumbled down slope, destroying the helicopter. Based upon flight path, terrain gradient and structural damage signatures, NTSB calculations indicated that the helicopter initially contacted the mountainside with a skid while descending in at least a 45-degree nose low pitch attitude. The engine and airframe wreckage were recovered, and no evidence of a mechanical malfunction was found.
Probable cause
the Board's determinationThe pilot's failure to maintain adequate terrain clearance/altitude while descending over mountainous terrain, and his continued flight into adverse weather. Factors contributing to the accident were clouds and a low ceiling.
NTSB analysis
from the final reportThe Title 14, CFR part 135 helicopter air tour flight was entering a mountainous crater. A passenger's videotape showed that the flight was initially performed in visual meteorological conditions, but as the helicopter approached the crater's 5,000-foot msl rim, its proximity to the clouds decreased, and the videotape ended. The videotape showed that the clouds were both above and below the helicopter. Recorded radar data, which ended about the time of the crash, showed that during the final few seconds of flight, the pilot maneuvered over the area, and its ground speed decreased from about 100 to 5 knots. Within the last 14 seconds of flight a descent was initiated, which increased in vertical speed to 2,000 feet per minute. The helicopter collided with the interior wall of the crater, and tumbled down slope, destroying the helicopter. Based upon flight path, terrain gradient and structural damage signatures, NTSB calculations indicated that the helicopter initially contacted the mountainside with a skid while descending in at least a 45-degree nose low pitch attitude. The engine and airframe wreckage were recovered, and no evidence of a mechanical malfunction was found.