What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
The aircraft was on a normal approach to the hover and as he transitioned into the hover the machine yawed to the right and the student lost control of the helicopter. Right yaw is usually caused by a drive train (tail rotor) failure , late application of left pedal to counteract the yaw due to power application or an aerodynamic effect caused by a left crosswind element referred to as loss of tail rotor effectiveness (lte)
The drive train was immediately inspected and showed full continuity and the winds on the day were out of the left side but quite light. It is possible he was late with left pedal application , a right yaw developed and lte resulted from allowing a rapid right yaw to develop un checked.
The student immediately lowered the collective lever resulting in the aircraft impacting on the taxi way on the left forward skid support fairing with rapid right rotation.
The aircraft then rocked backwards on its landing gear and the real tail rotor guard (stinger) impacted the taxi way exhibiting some impact deformation to the side.
Initial damage assessment
The landing gear did not yield as designed and deform to absorb impact energy as the impact point appeared to be exactly on the front left landing gear support.
The cabin area by the landing gear front cross member shows deformation and sheet metal damage , the rear door frame is distorted (but the door will close) , the tail boom is showing a crease on the left side on one section and some of the rear airframe sheet metal is showing a wavy deformation.
The vertical stabilizer shows some rippling damage following the stinger ground contact but there is no evidence of the tail rotor blades striking the ground.
There was no main rotor blade or tail rotor blade strike , the rear frames appear to be un damaged and the drive train is continuous indicating no sudden stoppage.
As the FAA filed it
THE AIRCRAFT WAS ON A NORMAL APPROACH TO THE HOVER AND AS HE TRANSITIONED INTO THE HOVER THE MACHINE YAWED TO THE RIGHT AND THE STUDENT LOST CONTROL OF THE HELICOPTER. RIGHT YAW IS USUALLY CAUSED BY A DRIVE TRAIN (TAIL ROTOR) FAILURE , LATE APPLICATION OF LEFT PEDAL TO COUNTERACT THE YAW DUE TO POWER APPLICATION OR AN AERODYNAMIC EFFECT CAUSED BY A LEFT CROSSWIND ELEMENT REFERRED TO AS LOSS OF TAIL ROTOR EFFECTIVENESS (LTE)
THE DRIVE TRAIN WAS IMMEDIATELY INSPECTED AND SHOWED FULL CONTINUITY AND THE WINDS ON THE DAY WERE OUT OF THE LEFT SIDE BUT QUITE LIGHT. IT IS POSSIBLE HE WAS LATE WITH LEFT PEDAL APPLICATION , A RIGHT YAW DEVELOPED AND LTE RESULTED FROM ALLOWING A RAPID RIGHT YAW TO DEVELOP UN CHECKED.
THE STUDENT IMMEDIATELY LOWERED THE COLLECTIVE LEVER RESULTING IN THE AIRCRAFT IMPACTING ON THE TAXI WAY ON THE LEFT FORWARD SKID SUPPORT FAIRING WITH RAPID RIGHT ROTATION.
THE AIRCRAFT THEN ROCKED BACKWARDS ON ITS LANDING GEAR AND THE REAL TAIL ROTOR GUARD (STINGER) IMPACTED THE TAXI WAY EXHIBITING SOME IMPACT DEFORMATION TO THE SIDE.
INITIAL DAMAGE ASSESSMENT
THE LANDING GEAR DID NOT YIELD AS DESIGNED AND DEFORM TO ABSORB IMPACT ENERGY AS THE IMPACT POINT APPEARED TO BE EXACTLY ON THE FRONT LEFT LANDING GEAR SUPPORT.
THE CABIN AREA BY THE LANDING GEAR FRONT CROSS MEMBER SHOWS DEFORMATION AND SHEET METAL DAMAGE , THE REAR DOOR FRAME IS DISTORTED (BUT THE DOOR WILL CLOSE) , THE TAIL BOOM IS SHOWING A CREASE ON THE LEFT SIDE ON ONE SECTION AND SOME OF THE REAR AIRFRAME SHEET METAL IS SHOWING A WAVY DEFORMATION.
THE VERTICAL STABILIZER SHOWS SOME RIPPLING DAMAGE FOLLOWING THE STINGER GROUND CONTACT BUT THERE IS NO EVIDENCE OF THE TAIL ROTOR BLADES STRIKING THE GROUND.
THERE WAS NO MAIN ROTOR BLADE OR TAIL ROTOR BLADE STRIKE , THE REAR FRAMES APPEAR TO BE UN DAMAGED AND THE DRIVE TRAIN IS CONTINUOUS INDICATING NO SUDDEN STOPPAGE.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.