Bell 47G N1420W accident near De Queen, Arkansas

Probable cause

The pilot's failure to conduct helicopter performance planning, which resulted in an uncontrolled descent and impact with a truck and terrain during takeoff from an elevated platform.

NTSB analysis

According to the pilot of the skid-equipped helicopter, he had loaded the helicopter with the liquid to be used during the agricultural aerial application flight. The pilot and operator both stated during interviews, that performance planning calculations were not performed prior to the flight, regarding adjustments pertaining to weight and balance, density altitude, out of ground effect capability or in ground effect capability. According to the operator, an FAA approved weight and balance form was not provided to the pilot until after the accident.

The pilot stated that during the takeoff from the elevated platform, he increased collective, established a 2 inch hover, applied forward cyclic, and the helicopter, "about a foot or two from the platform, shook violently and started to descend." The pilot recounted that he turned the nose of the helicopter approximately 45 degrees to the left and the main rotor blades impacted the tank truck upon which the elevated platform was mounted.

When asked, the pilot stated that, "the temperature was hot, possibly in the lower 80 degrees Fahrenheit, and no wind." The nearest weather station was 7 miles east of the accident site and reported 100 percent humidity, a temperature of 73.4 degrees Fahrenheit, a dew point of 73.4 degrees Fahrenheit, no wind and a density altitude of 1,698.7 feet, at an airport elevation of 355 feet. The accident site elevation was 457 feet.

The helicopter sustained substantial damage to the fuselage and main rotor system.

The pilot reported that there were no mechanical malfunctions or failures with the helicopter prior to the flight that would have precluded normal operation.

Text from the NTSB. Open the NTSB docket for GAA15CA202 for the full record.