Mcdonnell Douglas Helicopter 369 N540HH accident near Mesa, Arizona

Probable cause

The pilot receiving instruction’s failure to maintain helicopter control during autorotation, which resulted in a dynamic rollover. Contributing to the accident was the delayed remedial action from the flight instructor.

NTSB analysis

The flight instructor reported that, the pilot receiving instruction entered a smooth and established autorotation. About 75 ft above ground level, the pilot receiving instruction began to slow the helicopter into a near- vertical decent. The flight instructor took the controls, leveled the helicopter, and it then contacted the ground. One of the skids dug into the sand, and the helicopter proceeded to roll over. During the accident sequence, the helicopter sustained substantial damage to the tail boom, horizontal stabilizer, vertical stabilizer, and the fuselage.

The operator reported that there were no preaccident failures or malfunctions that precluded normal operation.

Text from the NTSB. Open the NTSB docket for WPR24LA239 for the full record.