What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) See attached pilot statement from deputy sinclair, the PIC for this flight. This investigation continues as of this date. However a SDR was submitted. Pilot's statement: shortly after takeoff from the lax west helipads, and extremely loud squeal and severe high-pitched vibration was heard/felt in the airframe. A "buzz" was felt in the anti-torque pedals. Altitude was approximately 300' and airspeed was 60 KIAS. The pitch of the vibration varied with pedal position. Engine systems instruments, N2 and rotor RPM were all in the green. A precautionary landing was made at the lax west helipads. When the vibration began, the aircraft was flying eastbound past the lax control tower. The tower operator advised that he could hear the squealing sound from inside the tower. Despite the vibration, the aircraft responded to flight control inputs as normal although a stiffness or binding was noted in the anti-torque pedals. Several hours earlier during the first flight of the evening, the binding in the pedals was first noted. The stiffness or binding was felt when the pedals were positioned at approximately 2" of right pedal beyond the neutral position. It was most noticeable d uring out of trim right orbits and landing approaches. The pedals would bind at that spot then become loose again beyond that point causing undesirable excessive yaw. This pedal stiffness has been encountered in the past with the 520N aircraft. Subsequent inspection by maintenance personnel revealed damage to several fan driveline components.
As the FAA filed it
(-23) SEE ATTACHED PILOT STATEMENT FROM DEPUTY SINCLAIR, THE PIC FOR THIS FLIGHT. THIS INVESTIGATION CONTINUES AS OF THIS DATE. HOWEVER A SDR WAS SUBMITTED. PILOT'S STATEMENT: SHORTLY AFTER TAKEOFF FROM THE LAX WEST HELIPADS, AND EXTREMELY LOUD SQUEAL AND SEVERE HIGH-PITCHED VIBRATION WAS HEARD/FELT IN THE AIRFRAME. A "BUZZ" WAS FELT IN THE ANTI-TORQUE PEDALS. ALTITUDE WAS APPROXIMATELY 300' AND AIRSPEED WAS 60 KIAS. THE PITCH OF THE VIBRATION VARIED WITH PEDAL POSITION. ENGINE SYSTEMS INSTRUMENTS, N2 AND ROTOR RPM WERE ALL IN THE GREEN. A PRECAUTIONARY LANDING WAS MADE AT THE LAX WEST HELIPADS. WHEN THE VIBRATION BEGAN, THE AIRCRAFT WAS FLYING EASTBOUND PAST THE LAX CONTROL TOWER. THE TOWER OPERATOR ADVISED THAT HE COULD HEAR THE SQUEALING SOUND FROM INSIDE THE TOWER. DESPITE THE VIBRATION, THE AIRCRAFT RESPONDED TO FLIGHT CONTROL INPUTS AS NORMAL ALTHOUGH A STIFFNESS OR BINDING WAS NOTED IN THE ANTI-TORQUE PEDALS. SEVERAL HOURS EARLIER DURING THE FIRST FLIGHT OF THE EVENING, THE BINDING IN THE PEDALS WAS FIRST NOTED. THE STIFFNESS OR BINDING WAS FELT WHEN THE PEDALS WERE POSITIONED AT APPROXIMATELY 2" OF RIGHT PEDAL BEYOND THE NEUTRAL POSITION. IT WAS MOST NOTICEABLE D URING OUT OF TRIM RIGHT ORBITS AND LANDING APPROACHES. THE PEDALS WOULD BIND AT THAT SPOT THEN BECOME LOOSE AGAIN BEYOND THAT POINT CAUSING UNDESIRABLE EXCESSIVE YAW. THIS PEDAL STIFFNESS HAS BEEN ENCOUNTERED IN THE PAST WITH THE 520N AIRCRAFT. SUBSEQUENT INSPECTION BY MAINTENANCE PERSONNEL REVEALED DAMAGE TO SEVERAL FAN DRIVELINE COMPONENTS.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.