Bell 47G 3B 1 N1181W accident near Carson City, Nevada

Probable cause

The pilot's failure to maintain sufficient main rotor rpm, which resulted in a loss of helicopter control and a dynamic rollover.

NTSB analysis

The private pilot was practicing takeoffs and landings to a taxiway. The pilot reported that, during his fourth landing attempt and as he was transitioning to a hover, he noticed that the helicopter's main rotor rpm was slightly low, and he attempted to increase the rpm by adding power. However, the helicopter did not respond and settled onto the taxiway. The pilot then raised the collective to bring the helicopter back to a hover, but the rotor rpm was still low. The pilot continued to try and add power, but the helicopter drifted right, and the right skid then contacted the ground off the side of the taxiway, which resulted in a dynamic rollover and substantial damage to the airframe and rotor blades.

The pilot stated that he was new to this type of helicopter, and it is likely that he allowed the main rotor rpm to decay to a point from which he was unable to recover. He stated that there were no preaccident mechanical anomalies with the helicopter that would have precluded normal operation.

Text from the NTSB. Open the NTSB docket for WPR16LA069 for the full record.