20200502018599A

ON 5/2/2020 AT 0205 CDT, N8375F, ^PRIVACY DATA OMITTED^, INC. MODEL 369E, S/N 0586F, REGISTERED TO THE ^PRIVACY DATA OMITTED^, AND OPERATED BY THE ^PRIVACY DATA OMITTED^ (HPD), IMPACTED AN APARTMENT COMPLEX OFFICE BUILDING NEAR THE INTERSECTION OF ^PRIVACY DATA OMITTED^. THE WEATHER WAS VMC AT THE TIME, AND NO FLIGHT PLAN WAS FILED. THE HELICOPTER WAS DESTROYED UPON IMPACT, WITH THE PILOT SUFFERING SERIOUS INJURIES AND THE ^PRIVACY DATA OMITTED^ OFFICER SUFFERING FATAL INJURIES. THERE WAS NO POST IMPACT FIRE. THE PILOT HOLDS A COMMERCIAL CERTIFICATE, WITH A SECOND CLASS MEDICAL CERTIFICATE, DATED JUNE 10, 2019. THE ACCIDENT SITE WAS MAPPED AND PHOTOGRAPHED BY THE ^PRIVACY DATA OMITTED^.

A WITNESS TOOK A ^PRIVACY DATA OMITTED^ THAT SHOWED THE HELICOPTER IN A ROTATION TO THE RIGHT SUBSEQUENT TO THE IMPACT WITH THE BUILDING. THE HELICOPTER IMPACTED THE NORTHEAST CORNER OF THE BUILDING, THEN ROLLED OFF THE BUILDING TO THE LEFT, COMING TO REST ON ITS LEFT SIDE BETWEEN THE BUILDING AND SEVERAL TREES. THE HELICOPTER WAS POINTED IN AN EASTERLY DIRECTION AT IT FINAL IMPACT POINT. THE COCKPIT PORTION OF THE FUSELAGE WAS HEAVILY DAMAGED DURING THE EXTRICATION PROCESS OF THE 2 CREWMEMBERS. AS EVIDENCED BY THE TRANSFER MARKS ON TOP OF THE BUILDING, THE AIRFRAME CAME DOWN ON THE ROOF OF THE BUILDING WITH NO FORWARD MOMENTUM AND AT A LEVEL ATTITUDE. THE RIGHT-HAND SKID TUBE WAS VISIBLY DEFINED ON THE ROOF MATERIAL, AS WELL AS SCUFF MARKS FROM THE FORWARD LOOKING INFRARED RADAR (FLIR) SYSTEM CAMERA AND THE NIGHTSUN UNIT. A CLEAR TRANSFER OF ROOF MATERIAL WAS EVIDENT ON THE FLIR UNIT.

THE MAIN ROTOR HUB APPEARED TO BE INTACT, WITH DAMAGE NOTED TO SEVERAL OF THE MAIN ROTOR BLADE DAMPER ASSEMBLIES. 4 OF THE 5 MAIN ROTOR PITCH CHANGE (PC) LINKS WERE STILL ATTACHED, THE 5TH PC LINK (GREEN) WAS SHEERED AT ROD END THREADS. THE GREEN PC LINK WAS LOCATED IN THE WRECKAGE AND EXHIBITED SHEAR DISTRESS THROUGH THE THREADS OF THE ROD ENDS. ALL 5 MAIN ROTOR BLADES WERE ACCOUNTED FOR AND, OTHER THAN THE BLADE THAT WAS FOLDED UNDERNEATH THE FUSELAGE, WERE RELATIVELY INTACT AND SHOWED NO SIGNS OF DAMAGE THAT WOULD BE TYPICAL WITH POSITIVE ROTOR INERTIA AT TIME OF IMPACT. THERE WAS PAINT TRANSFER ON TWO MAIN ROTOR BLADES LEADING EDGE, WHICH MAY INDICATE THAT THESE BLADE MADE CONTACT WITH THE TAILBOOM ASSEMBLY ON IMPACT. THE TAILBOOM EXHIBITED IMPACT DAMAGE, ALONG WITH SHEAR OR SEPARATION DAMAGE THROUGH THE STRUCTURE, TAIL ROTOR DRIVESHAFT AND TAIL CONTROL TUBE. THE VERTICAL FIN, HORIZONTAL STABILIZER AND TAIL ROTOR HUB AND FORK ASSEMBLY WERE SEPARATED FROM THE TAILBOOM. THE TAIL ROTOR BLADES EXHIBITED VERY LITTLE DAMAGE CONSISTENT WITH THE TAIL ROTOR ASSEMBLY NOT UNDER POWER AT THE TIME OF IMPACT.

AIRCRAFT MAINTENANCE RECORDS INDICATE THAT THE LAST MAJOR INSPECTION COMPLETED WAS AN ANNUAL/100 HOUR INSPECTION ON MARCH 18, 2020, AT AFTT: 4700.7. AN IN-HOUSE 25 HOUR INSPECTION WAS COMPLETED AT AFTT: 4775.3; THIS 25 HOUR INSPECTION IS AN OWNER-OPERATOR PRODUCED INSPECTION. THE ESTIMATED AIRFRAME TOTAL TIME AT THE TIME OF THE ACCIDENT WAS 4788. THE HELICOPTER HAD FLOWN 1.6 HOURS ON A PRIOR FLIGHT ON MAY 1, 2020, BETWEEN THE HOURS OF 2200-2330. THE PILOT-IN-COMMAND ON THE ACCIDENT FLIGHT WAS THE PILOT WHO FLEW THE HELICOPTER ON THE PREVIOUS FLIGHT.

FROM THE PILOT?S STATEMENT: PRIOR TO THE ACCIDENT, THE PILOT INDICATED THAT THERE HAD BEEN NO MECHANICAL ISSUES WITH THE HELICOPTER. AT THE SCENE, THEY WERE ORBITING TO THE RIGHT AT AN ALTITUDE OF 700 ? 1000 FEET BUT HE WAS UNSURE OF HIS AIRSPEED AT THE TIME. HE STATED THAT THEY TYPICALLY ORBIT AT 30 KNOTS AND ABOVE. THE AIRCRAFT GROSS WEIGHT WAS APPROXIMATELY 2823 LBS. WHEN THE INCIDENT OCCURRED, HE BEGAN PERFORMING THE EMERGENCY PROCEDURE FOR LOSS OF TAIL ROTOR.WRECKAGE WAS EXAMINED ON MARCH 30-31, 2021, WITH EMPHASIS PLACED ON THE T/R DRIVE AND T/R FLIGHT CONTROLS. CONTINUITY OF THE SYSTEMS WAS CONFIRMED. THE ENGINE WAS EXAMINED WITH NO OBVIOUS ANOMALIES NOTED.