On November 2, 2002, a Bell 47G-2 (registration N2616B) operated by D. C. Rotor & Wing was involved in an aviation accident near Pollock Pines, CA. Investigators recorded the probable cause as: The pilot's failure to maintain adequate clearance from terrain and obstacles during the initial climb, which resulted in the skids colliding with a bush. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A helicopter collided with a bush while climbing from a plateau at 3,500 feet MSL. The pilot increased collective pitch to accelerate toward effective translational lift when the skid struck the vegetation.
What happened
The accident occurred during the initial climb phase of flight from a plateau situated at an elevation of 3,500 feet mean sea level. As the helicopter ascended, its skids made contact with a bush that stood approximately three feet high. Following this impact, the aircraft experienced an uncommanded yawing motion and subsequently struck the ground.
The pilot provided a report detailing the sequence of events leading to the collision. He stated that he had increased the collective pitch control to gain altitude and was accelerating the helicopter to approximately 20 knots. This maneuver was intended to help the aircraft acquire effective translational lift, a critical phase in helicopter flight dynamics where forward airspeed reduces the power required to maintain hover.
Probable cause
The pilot's failure to maintain adequate clearance from terrain and obstacles during the initial climb, which resulted in the skids colliding with a bush.