Incident Description
During a rotorcraft instructional flight, the instructor planned to conclude with a practice forced landing involving a power recovery at 500 feet above ground level (AGL). The instructor did not disarm the engine governor beforehand. When the instructor announced "engine failure," the student rolled the throttle to the detent and held it there. The instructor subsequently attempted to ease on the throttle but felt resistance, which he interpreted as a genuine engine failure, leading him to announce "my controls."
Contributing Factors
The landing spot chosen had grass that was too high and terrain that was uneven and soft. Additionally, the student continued handling the collective control, despite the instructor taking over. The combination of these factors resulted in a flare that was too high, leading to a hard touchdown and subsequent rollover.