What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
N618SG, a HU369E on a part 135 revenue flight, lost control during its landing approach just prior to touchdown at a 8300 ft MSL mountain landing zone (lz) near Wrightwood ski resort. N618SG rolled over after contacting the ground sustaining substantial damage. Three persons on board; minor injuries.
Prior to the flight, the PIC performed weight and balance calculations as well as aircraft performance calculations. N618SG was determined to be under its maximum gross weight of 3000 lbs by 133.4 lbs and the center of gravity (CG) within limits (longitudinal and lateral). The PIC stated that the calculated hover in ground effect (hige) altitude was 8600 ft.
Prior to landing, the PIC performed an available power check by slowing to a near hover, pulling power to redline turbine outlet temperature (tot) which yielded a small climb rate. The PIC felt that his weight and performance calculations gave him an adequate safety margin. The PIC also performed several orbits (high reconnaissance) of the lz to determine the wind direction and estimated velocity. No wind in the vicinity of the proposed landing zone (lz), a dirt road, was detected.
N618SG began a landing approach on a northeasterly heading, turning to a easterly heading to land on a level area of the road. As the aircraft slowed below effective translational lift (etl), it began a slow, right turn which quickly became a rapid uncommanded right turn to the south. The PIC applied full left pedal to counteract the right turn and applied forward cyclic to fly out of the apparent loss of tail rotor effectiveness (lte) situation.
As N618SG was flying downslope south of the lz on a southerly heading, it snagged a portion of the thick underbrush. N618SG pitched nose down, the main rotor system striking the ground. N618SG came to rest on its left side, facing on a heading of 310 degrees.
As the FAA filed it
N618SG, A HU369E ON A PART 135 REVENUE FLIGHT, LOST CONTROL DURING ITS LANDING APPROACH JUST PRIOR TO TOUCHDOWN AT A 8300 FT MSL MOUNTAIN LANDING ZONE (LZ) NEAR WRIGHTWOOD SKI RESORT. N618SG ROLLED OVER AFTER CONTACTING THE GROUND SUSTAINING SUBSTANTIAL DAMAGE. THREE PERSONS ON BOARD; MINOR INJURIES.
PRIOR TO THE FLIGHT, THE PIC PERFORMED WEIGHT AND BALANCE CALCULATIONS AS WELL AS AIRCRAFT PERFORMANCE CALCULATIONS. N618SG WAS DETERMINED TO BE UNDER ITS MAXIMUM GROSS WEIGHT OF 3000 LBS BY 133.4 LBS AND THE CENTER OF GRAVITY (CG) WITHIN LIMITS (LONGITUDINAL AND LATERAL). THE PIC STATED THAT THE CALCULATED HOVER IN GROUND EFFECT (HIGE) ALTITUDE WAS 8600 FT.
PRIOR TO LANDING, THE PIC PERFORMED AN AVAILABLE POWER CHECK BY SLOWING TO A NEAR HOVER, PULLING POWER TO REDLINE TURBINE OUTLET TEMPERATURE (TOT) WHICH YIELDED A SMALL CLIMB RATE. THE PIC FELT THAT HIS WEIGHT AND PERFORMANCE CALCULATIONS GAVE HIM AN ADEQUATE SAFETY MARGIN. THE PIC ALSO PERFORMED SEVERAL ORBITS (HIGH RECONNAISSANCE) OF THE LZ TO DETERMINE THE WIND DIRECTION AND ESTIMATED VELOCITY. NO WIND IN THE VICINITY OF THE PROPOSED LANDING ZONE (LZ), A DIRT ROAD, WAS DETECTED.
N618SG BEGAN A LANDING APPROACH ON A NORTHEASTERLY HEADING, TURNING TO A EASTERLY HEADING TO LAND ON A LEVEL AREA OF THE ROAD. AS THE AIRCRAFT SLOWED BELOW EFFECTIVE TRANSLATIONAL LIFT (ETL), IT BEGAN A SLOW, RIGHT TURN WHICH QUICKLY BECAME A RAPID UNCOMMANDED RIGHT TURN TO THE SOUTH. THE PIC APPLIED FULL LEFT PEDAL TO COUNTERACT THE RIGHT TURN AND APPLIED FORWARD CYCLIC TO FLY OUT OF THE APPARENT LOSS OF TAIL ROTOR EFFECTIVENESS (LTE) SITUATION.
AS N618SG WAS FLYING DOWNSLOPE SOUTH OF THE LZ ON A SOUTHERLY HEADING, IT SNAGGED A PORTION OF THE THICK UNDERBRUSH. N618SG PITCHED NOSE DOWN, THE MAIN ROTOR SYSTEM STRIKING THE GROUND. N618SG CAME TO REST ON ITS LEFT SIDE, FACING ON A HEADING OF 310 DEGREES.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.