What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
During a 14 CFR 61 training flt the CFI had the student initiate a practice 180 degree autorotation with the intention of a termination with power. As they initiated the power recovery the CFI noted the rate of descent was not dissipating and so he took the controls and intended to perform a go-around. However, the aircraft failed to gain altitude and slid onto the runway at a relative high rate. The impact caused the main rotor to flex and it struck the tail boom. There may be more extensive damage. A FSDO ASI conducted an on-site inspection and confirmed substantial damage. After further investigation and interviewing the CFI a 44709 action was conducted successfully.
As the FAA filed it
DURING A 14 CFR 61 TRAINING FLT THE CFI HAD THE STUDENT INITIATE A PRACTICE 180 DEGREE AUTOROTATION WITH THE INTENTION OF A TERMINATION WITH POWER. AS THEY INITIATED THE POWER RECOVERY THE CFI NOTED THE RATE OF DESCENT WAS NOT DISSIPATING AND SO HE TOOK THE CONTROLS AND INTENDED TO PERFORM A GO-AROUND. HOWEVER, THE AIRCRAFT FAILED TO GAIN ALTITUDE AND SLID ONTO THE RUNWAY AT A RELATIVE HIGH RATE. THE IMPACT CAUSED THE MAIN ROTOR TO FLEX AND IT STRUCK THE TAIL BOOM. THERE MAY BE MORE EXTENSIVE DAMAGE. A FSDO ASI CONDUCTED AN ON-SITE INSPECTION AND CONFIRMED SUBSTANTIAL DAMAGE.AFTER FURTHER INVESTIGATION AND INTERVIEWING THE CFI A 44709 ACTION WAS CONDUCTED SUCCESSFULLY.