What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(.19) See NTSB #LAX02LA137 (-23) instructor was letting student lift aircraft from a slight slope, right skid low. As student applied collective at 3100 RPM a vibration occured, the instructor took controls lowered collective and reduced throttle, vibration went away, the instructor then attempted to raise the aircraft at 3100 RPM and the vibration started again, he lowered collective and reduced power, but the vibration continued and got more violent, the rotor tore the transmission from its mounts, chopped the tailboom and basically beat its self to destruction. Pilot admitted that he did not preflight the dampners orthe strut shocks. Believed aircraft was in ground resonance and pilot made wrong input.
As the FAA filed it
(.19) SEE NTSB #LAX02LA137 (-23) INSTRUCTOR WAS LETTING STUDENT LIFT AIRCRAFT FROM A SLIGHT SLOPE, RIGHT SKID LOW. AS STUDENT APPLIED COLLECTIVE AT 3100 RPM A VIBRATION OCCURED, THE INSTRUCTOR TOOK CONTROLS LOWERED COLLECTIVE AND REDUCED THROTTLE, VIBRATION WENT AWAY, THE INSTRUCTOR THEN ATTEMPTED TO RAISE THE AIRCRAFT AT 3100 RPM AND THE VIBRATION STARTED AGAIN, HE LOWERED COLLECTIVE AND REDUCED POWER, BUT THE VIBRATION CONTINUED AND GOT MORE VIOLENT, THE ROTOR TORE THE TRANSMISSION FROM ITS MOUNTS, CHOPPED THE TAILBOOM AND BASICALLY BEAT ITS SELF TO DESTRUCTION. PILOT ADMITTED THAT HE DID NOT PREFLIGHT THE DAMPNERS ORTHE STRUT SHOCKS. BELIEVED AIRCRAFT WAS IN GROUND RESONANCE AND PILOT MADE WRONG INPUT.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.