What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Aircraft privacy data omitted, EC-120 helicopter, lost control directional control at approximately 325 feet above the ground. The helicopter flight crew was conducting an approach to an urban landing area for training. The pilot on the controls allowed the aircraft to slow below effective translational lift (etl) while in a left turn from base to final. Both pilots felt the transition below etl, and the certified flight instructor verbally requested the pilot flying to increase airspeed. The aircraft began an uncommanded left turn. The pilot on the controls did not recognize the onset of loss of tail rotor effectiveness (lte) and did not immediately apply corrective measures. The aircraft left yaw rate increased, and the pilot-in-command/flight instructor took control of the helicopter. The pilot-in-command attempted to regain control by lowering the collective and forward cyclic. The pilot-in-commnad could not fully restore helicopter control before impacting the ground. The helicopter made approximately eight rotations before making contact with the ground. Upon impact, the helicopter bounced about fifteen feet with one more spin before coming to rest in the upright position. The landing skids were fully collapsed, with the right side taking most of the impact, collapsing the fuselage underside on the right side. The flight crew performed an emergency shutdown—no known damage to the main rotor system, tail boom, or tail rotor. The engine was operating normally until shutdown. There are no previous maintenance discrepancies with the tail rotor system.
As the FAA filed it
AIRCRAFT ^PRIVACY DATA OMITTED^, EC-120 HELICOPTER, LOST CONTROL DIRECTIONAL CONTROL AT APPROXIMATELY 325 FEET ABOVE THE GROUND. THE HELICOPTER FLIGHT CREW WAS CONDUCTING AN APPROACH TO AN URBAN LANDING AREA FOR TRAINING. THE PILOT ON THE CONTROLS ALLOWED THE AIRCRAFT TO SLOW BELOW EFFECTIVE TRANSLATIONAL LIFT (ETL) WHILE IN A LEFT TURN FROM BASE TO FINAL. BOTH PILOTS FELT THE TRANSITION BELOW ETL, AND THE CERTIFIED FLIGHT INSTRUCTOR VERBALLY REQUESTED THE PILOT FLYING TO INCREASE AIRSPEED. THE AIRCRAFT BEGAN AN UNCOMMANDED LEFT TURN. THE PILOT ON THE CONTROLS DID NOT RECOGNIZE THE ONSET OF LOSS OF TAIL ROTOR EFFECTIVENESS (LTE) AND DID NOT IMMEDIATELY APPLY CORRECTIVE MEASURES. THE AIRCRAFT LEFT YAW RATE INCREASED, AND THE PILOT-IN-COMMAND/FLIGHT INSTRUCTOR TOOK CONTROL OF THE HELICOPTER. THE PILOT-IN-COMMAND ATTEMPTED TO REGAIN CONTROL BY LOWERING THE COLLECTIVE AND FORWARD CYCLIC. THE PILOT-IN-COMMNAD COULD NOT FULLY RESTORE HELICOPTER CONTROL BEFORE IMPACTING THE GROUND. THE HELICOPTER MADE APPROXIMATELY EIGHT ROTATIONS BEFORE MAKING CONTACT WITH THE GROUND. UPON IMPACT, THE HELICOPTER BOUNCED ABOUT FIFTEEN FEET WITH ONE MORE SPIN BEFORE COMING TO REST IN THE UPRIGHT POSITION. THE LANDING SKIDS WERE FULLY COLLAPSED, WITH THE RIGHT SIDE TAKING MOST OF THE IMPACT, COLLAPSING THE FUSELAGE UNDERSIDE ON THE RIGHT SIDE. THE FLIGHT CREW PERFORMED AN EMERGENCY SHUTDOWN—NO KNOWN DAMAGE TO THE MAIN ROTOR SYSTEM, TAIL BOOM, OR TAIL ROTOR. THE ENGINE WAS OPERATING NORMALLY UNTIL SHUTDOWN. THERE ARE NO PREVIOUS MAINTENANCE DISCREPANCIES WITH THE TAIL ROTOR SYSTEM.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.