What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
On June 13, 2018 at approximately 1146 PST, at North Las Vegas airport (kvgt), a 1993 Schweizer 269C sustained substantial damage due to ground resonance.
The aircraft was parked on the south ramp in a marked helicopter pad where the pilot was preparing to lift into a hover. The pilot stated the helicopter began to vibrate prior to becoming light on the skids. As the vibrations increased, the pilot lowered the collective and rolled off the throttle.
The pilot reported that the vibrations became even more severe for approximately 20 to 40 seconds until the rotor blades came to a stop due to substantial damage caused by the vibrations.
An inspection of the four landing gear dampers and the only undamged rotor oleo elastomeric damper, all tested within allowed tolerances.
As the FAA filed it
ON JUNE 13, 2018 AT APPROXIMATELY 1146 PST, AT NORTH LAS VEGAS AIRPORT (KVGT), A 1993 SCHWEIZER 269C SUSTAINED SUBSTANTIAL DAMAGE DUE TO GROUND RESONANCE.
THE AIRCRAFT WAS PARKED ON THE SOUTH RAMP IN A MARKED HELICOPTER PAD WHERE THE PILOT WAS PREPARING TO LIFT INTO A HOVER. THE PILOT STATED THE HELICOPTER BEGAN TO VIBRATE PRIOR TO BECOMING LIGHT ON THE SKIDS. AS THE VIBRATIONS INCREASED, THE PILOT LOWERED THE COLLECTIVE AND ROLLED OFF THE THROTTLE.
THE PILOT REPORTED THAT THE VIBRATIONS BECAME EVEN MORE SEVERE FOR APPROXIMATELY 20 TO 40 SECONDS UNTIL THE ROTOR BLADES CAME TO A STOP DUE TO SUBSTANTIAL DAMAGE CAUSED BY THE VIBRATIONS.
AN INSPECTION OF THE FOUR LANDING GEAR DAMPERS AND THE ONLY UNDAMGED ROTOR OLEO ELASTOMERIC DAMPER, ALL TESTED WITHIN ALLOWED TOLERANCES.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.
Other reports on N557DC · 3
Matched to the same aircraft by N-number and date.