Background
A flight instructor was supervising a student pilot practicing solo "pickups and set downs" on a grass area at an airport. The instructor exited the helicopter and watched as the student successfully lifted to a hover and set down without incident during the first iteration.
Accident Sequence
During the second attempt, the student pilot brought the helicopter to a hover at 5 to 8 feet above ground level and held it for several seconds. The helicopter then began a slow right yaw, which continued until it had turned 270 degrees from its original heading. Subsequently, the helicopter lost altitude and moved forward, causing the skids to contact the ground. The helicopter bounced back into the air, rolled slightly left, then abruptly rolled right, the nose pitched down, and the main rotor blades struck the ground. The helicopter came to rest on its right side.
Aftermath
The flight instructor reported entering the cockpit to shut off the engine. The helicopter sustained substantial damage to the fuselage, main rotor system, tailboom, and horizontal stabilizer. The student pilot did not recall the accident sequence. At the hospital, the student told the instructor, "I should have been able to control it [the helicopter]."
Investigation
A Federal Aviation Administration aviation safety inspector examined the accident site. The inspector found no signs of mechanical control issues with the helicopter, and the engine showed no problems. Witnesses stated the engine was still running after the ground impact. The flight instructor confirmed there were no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.
Recommendations
The flight instructor stated that her organization would increase training syllabus time to emphasize light control inputs and the potential for overcontrolling, especially during hover. The FAA Helicopter Flying Handbook (FAA-H-8083-21, 2012) advises that to maintain a stabilized hover, pilots should make small, smooth, coordinated corrections.