On July 31, 1992, a Hughes 369D (registration N64MK) operated by Pce, Ltd. was involved in an aviation accident near Honolulu, HI. Investigators recorded the probable cause as: THE STUDENT'S IMPROPER USE OF THE FLIGHT CONTROLS DURING AN ATTEMPTED RECOVERY FROM AN OVER ROTATION DURING THE FLARE, AND, THE FLIGHT INSTRUCTOR'S INADEQUATE SUPERVISION OF THE FLIGHT. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During a check flight for a new flight instructor, an auto rotation practice resulted in a hard landing that severed the tail boom.
Incident Overview
According to statements from both pilots, the flight was conducted to evaluate a new flight instructor on the helicopter type. While practicing an autorotation to touchdown, the new flight instructor over-rotated during the flare, causing the tail skid to scrape the pavement.
Sequence of Events
The new flight instructor reported that he then pulled up on the collective, causing the helicopter to balloon upward to approximately 15 feet above ground level. With main rotor speed low, the helicopter subsequently landed hard. The main rotor flexed downward and severed the tail boom.
Instructor Input
The flight instructor who was checking out the new pilot stated that he had his hands on the controls during the maneuver but was unable to correct for the unexpected input by the new instructor in time to prevent the balloon and the subsequent hard landing.