On February 26, 2000, a Bell 412 (registration N411UT) was involved in an aviation accident near Karns, TN. Investigators recorded the probable cause as: The pilot's failure to maintain clearance from a tree while maneuvering the helicopter in a hover, which resulted in a tail rotor strike. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A helicopter pilot attempted to reposition after landing on steep terrain to assist injured personnel. While hovering and observing obstacles, the tail rotor struck a tree.
What happened
The pilot landed at a designated landing zone with the objective of retrieving injured personnel from the site. Upon assessment of the terrain, it was determined that the slope was too steep for safe operations in that position. To address this, the pilot initiated a repositioning maneuver by lifting the helicopter into a hover.
While maintaining the hover, the pilot directed attention toward the left side of the aircraft to monitor proximity to wires located near a driveway. During this phase of flight, the pilot rotated the tail of the helicopter to the right. This movement resulted in the tail rotor colliding with a tree that was 15 feet tall.
The investigation
The investigation focused on the mechanical condition of the aircraft following the impact and the operational circumstances surrounding the event. Examination confirmed damage to the tail rotor assembly consistent with the reported collision with the tree.
Probable cause
The pilot's failure to maintain clearance from a tree while maneuvering the helicopter in a hover, which resulted in a tail rotor strike.