What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) Instructor pilot privacy data omitted ^ and student privacy data omitted were performing 180 degree autorotations to a grass area at Grand Prairie muni airport, Texas. Student was going to be too low/slow so instructor took controls and completed running landing. Touch down was good but while skidding to a stop, the left skid encountered a soft spot and dug in, nosing the aircraft over straight ahead. Rotor struck the ground and broke up. The aircraft came to a stop on its right side. There were no injuries and no fire. The tail-cone sustained a slight wrinkle, thus the substantial damage.
As the FAA filed it
(-23) INSTRUCTOR PILOT ^PRIVACY ^ AND STUDENT ^PRIVACY DATA^ WERE PERFORMING 180 DEGREE AUTOROTATIONS TO A GRASS AREA AT GRAND PRAIRIE MUNI AIRPORT, TEXAS. STUDENT WAS GOING TO BE TOO LOW/SLOW SO INSTRUCTOR TOOK CONTROLS AND COMPLETED RUNNING LANDING. TOUCH DOWN WAS GOOD BUT WHILE SKIDDING TO A STOP, THE LEFT SKID ENCOUNTERED A SOFT SPOT AND DUG IN, NOSING THE AIRCRAFT OVER STRAIGHT AHEAD. ROTOR STRUCK THE GROUND AND BROKE UP. THE AIRCRAFT CAME TO A STOP ON ITS RIGHT SIDE. THERE WERE NO INJURIES AND NO FIRE. THE TAIL-CONE SUSTAINED A SLIGHT WRINKLE, THUS THE SUBSTANTIAL DAMAGE.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.