On June 26, 2005, a Schweizer 269C (registration N308BP) was involved in an aviation accident near Broomfield, CO. Investigators recorded the probable cause as: the pilot's failure to maintain adequate rotor rpm which resulted in a loss of control and an uncontrolled descent. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During a normal approach, the pilot noted rotor droop, then the tail snapped left, the helicopter rotated clockwise, and the low rotor rpm warning activated. The helicopter impacted the ramp upright, collapsing the right skid and striking the tail rotor.
Accident Sequence
During a normal approach, the pilot observed a slight "rotor droop." Immediately following, the tail of the helicopter "snapped left," the helicopter began rotating clockwise, and the LOW ROTOR RPM warning activated.
Pilot Actions
In response, the pilot pushed the cyclic forward and applied "up collective" in an attempt to slow the descent rate. He stated that he was unable to apply further forward cyclic input due to other aircraft operating in the vicinity.
Impact and Damage
The helicopter subsequently impacted the ramp in an upright attitude. The right skid collapsed further than the left skid. The tail rotor struck the ground, and the tail boom cracked.