DILLON, MT, USA
N2277T
BELL 206
THE PILOT LANDED AT A REMOTE SNOW-SURVEY SITE, AND THEN MOVED THE CYCLIC IN A CIRCLE TO TEST WHETHER THE SNOW WOULD SUPPORT THE WEIGHT OF THE HELICOPTER. SENSING THAT THE SNOW WAS FIRM ENOUGH TO SUPPORT THE HELICOPTER'S WEIGHT, THE PILOT ELECTED TO SHUT DOWN THE ENGINE. AFTER HE HAD SHUT OFF THE ENGINE AND THE ROTOR WAS DECELERATING, ONE OF THE SNOWPAD-EQUIPPED SKIDS BROKE THROUGH THE SNOW. AS THE SKID BROKE THROUGH THE SNOW, THE TAIL ROTOR IMPACTED THE SNOW AND THEN CONTACTED THE TAIL BOOM CAUSING SUBSTANTIAL DAMAGE.
On February 24, 1995, approximately 1030 mountain standard time (MST), the tail rotor of a Bell 206, N2277T, impacted the snow as the pilot was shutting down the aircraft about 42 miles southwest of Dillon, Montana. The commercial pilot and his passenger were not injured, but the helicopter sustained substantial damage. The Public Use snow-survey flight, which departed another remote site about 1000 that morning, had landed on the snow pack in order for the Soil Conservation Service to measure the snow depth. The aircraft was being operated in visual meteorological conditions at the time of the accident. No flight plan had been filed, and there was no report of an ELT activation. According to the pilot, he set the helicopter down on the snow and rotated the cyclic in a circle in order to check the firmness of the snowpack before shutting down. Because the snow appeared to be firm enough to hold the weight of the helicopter, he decided it would be all right to shut down the engine. As he shut off the engine and the main rotor began to decelerate, one of the skids broke through the snow, and the tail rotor impacted the snow, and then struck the tail boom. The helicopter's skids were equipped with snowpads. The pilot did not return pages three and five of NTSB Form 6120.1/2.
THE PILOT'S SELECTION OF A LANDING SITE THAT WAS NOT SUITABLE TO SUPPORT THE WEIGHT OF THE HELICOPTER. FACTORS INCLUDE TERRAIN COVERED WITH SOFT SNOW.
Source: NTSB Aviation Accident Database
Aviation Accidents App
In-Depth Access to Aviation Accident Reports
