Helicopter Accident During Agricultural Flight (N43921)

Accident Sequence

After the helicopter was reloaded with 500 lbs of sulfur, the pilot departed to the northwest at an altitude of about 100 ft to continue the application mission. The ground crew reported that shortly after departure, the engine backfired several times and the helicopter began settling tail first to the ground. Ground contact separated the tail boom from the helicopter, and it rotated to the left. The skids separated, and the right sulfur tank ruptured. A sulfur fire erupted. The pilot exited the cockpit on the right side and was struck by the main rotor.

Weight and Loading

The helicopter was loaded 69 lbs over its maximum allowable gross weight. No preimpact part failure of the helicopter or engine was found.

Toxicology

Tests of the pilot's blood showed 0.009 µg/mL of 11-nor-delta-9-tetrahydrocannabinol and 0.012 µg/mL of 11-nor-delta-9-THC-9-carboxylic acid. A test of his urine detected 0.129 µg/mL of 11-nor-delta-9-carboxylic acid.