Eurocopter EC130 N55GJ accident near Knoxville, Tennessee

Probable cause

The pilot's entry into vortex ring state and his inability to arrest the helicopter's descent while maneuvering for landing.

NTSB analysis

The helicopter pilot was returning to his property located adjacent to a river. As the helicopter descended toward the water at a 25° angle with low forward airspeed, the pilot applied power to arrest the descent. However, the helicopter continued to descend until it impacted the river short of the intended landing area. The pilot and two passengers survived the impact and a third passenger drowned.

The investigation revealed no preimpact mechanical malfunctions or anomalies that would have prevented the normal operation of the helicopter. Recovered flight data indicated the engine was producing power at the time of impact. Weather reports and statements from the pilot and witnesses indicated that the helicopter descended steeply with little forward airspeed and a tailwind of about 5 knots, which is a flight profile conducive to vortex ring state. The pilot’s reported lack of collective authority when increasing power to arrest the helicopter’s descent is also consistent with the helicopter entering vortex ring state. A pilot's failure to monitor altitude, airspeed, and rate of descent during an approach can result in a flight profile conducive to vortex ring state.

Text from the NTSB. Open the NTSB docket for ERA20LA273 for the full record.