N878CBRobinson Helicopter R44 II · 2004

The pilot reported that he was conducting helicopter external sling load operations to a remote mountain top. At the drop off site, while in a hover about 20 ft above the ground, with his attention focused outside to ensure he cleared terrain and obstacles, he felt the helicopter begin to settle. The rpm began to decay, the low rotor rpm light illuminated, and the horn sounded. He immediately lowered the collective, released the cargo and impacted the ground coming to rest on top of the cargo. The helicopter sustained substantial damage to the rotor system and vertical stabilizer.

The pilot reported that there were no preaccident mechanical malfunctions or anomalies with the helicopter that would have precluded normal operation, and that the accident may have been prevented if he had received additional training from the company to include flying at gross weight with and without external loads. In addition to having pilots check for available power in an out-of-ground effect hover with altitudes and escape routes before committing to the approach.

The pilot reported that, after landing on an elevated helicopter deck and reducing the rotor RPM, he signaled for the brush cutting ground crew leader to approach the helicopter to collect additional chainsaw bars that were being dropped off. He added that, the crew leader indicated that two of the three chainsaw bars were not the correct bars needed, and then threw an incorrect bar away from the helicopter. Subsequently, the bar impacted a main rotor blade, which resulted in substantial damage.

The pilot reported that the brush cutting crew had been briefed before operations on gear security, rotor awareness, and safe practices when working around the helicopter. The crew leader admitted to a lapse in judgment brought on by stress and frustration.

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