NTSB Identification: ANC01TA035.
The docket is stored in the Docket Management System (DMS). Please contact Records Management Division
Accident occurred Sunday, February 04, 2001 in Chickaloon, AK
Probable Cause Approval Date: 08/21/2001
Aircraft: Robinson R-44, registration: N7183P
Injuries: 3 Uninjured.
NTSB investigators may have traveled in support of this investigation and used data provided by various sources to prepare this public aircraft accident report.
The pilot was transporting two search and rescue volunteers and their equipment to the scene of an avalanche in a float-equipped helicopter. A helicopter landing zone (heli spot) had been established the evening before the accident, near the toe of the avalanche. The heli spot had been used by a military helicopter, and was marked by small flags. The surface of the snow at the heli spot had been dusted by red powder. The pilot of the accident helicopter had not landed at the heli spot before. The heli spot was located at 5,300 feet msl, near the bottom of a small valley. The pilot began his landing approach toward the west. Although the weather conditions were clear, the pilot said the lighting conditions in the valley provided little contrast (flat light). The pilot said that as he began to add power near the termination of the landing approach, the low rotor warning horn sounded, and he noticed that the main rotor gauge was indicating 92 to 94 percent. He reduced collective pitch, ensured the throttle was full open, and began to initiate a go-around toward the west, an area of lower terrain. The helicopter continued to descend, and the right front portion of the landing gear float assembly contacted the snow. About the same time, the main rotor contacted the slope of a small, snow-covered hill, to the right of the helicopter. The helicopter then rolled onto its right side. After the accident, the pilot said he noted that the wind was blowing about 8 knots from the east.
The National Transportation Safety Board determines the probable cause(s) of this accident to be: The pilot's collision with terrain due to his inadequate planning of the approach, and his failure to maintain the helicopter's main rotor RPM during a go-around. Factors in the accident were a tailwind, flat lighting conditions, and snow-covered terrain. Full narrative available
Index for Feb2001 | Index of months