Robinson Helicopter R22 N74583 accident near Springfield, Missouri

Probable cause

The pilot’s failure to maintain directional control and the flight instructor’s lack of proper remedial action during the practice autorotation that resulted in the helicopter impacting terrain. Contributing to the accident was the presence of the gusting wind condition and the presence of speed shear.

NTSB analysis

Prior to the training flight, the flight instructor received an official weather briefing from a commercial source, and the terminal area forecast reported for high winds later in the day. The flight instructor and the pilot receiving instruction were practicing autorotations in the helicopter at the airport.

During the last autorotation, after the entry and the engine power at idle, the flight instructor told the pilot to “steer” multiple times and he even gave the cyclic a “nudge.” The helicopter was oriented to about a 240° heading while drifting past the runway centerline to the south. The helicopter was drifting to the left and the flight instructor reported the pilot was unable to turn the helicopter to the right. The helicopter continued to travel to the south beyond airport property toward a public sports complex. The flight instructor initiated a flare. The helicopter impacted a grass field upright near trees in the public sports complex, and it came to rest on its left side. The helicopter sustained substantial damage to the fuselage, the main rotor system, the tail cone, the empennage, and the tail rotor system.

The flight instructor was unsure if there was a flight control malfunction and he thought that if there was a flight control malfunction, initiating a power recovery during the autorotation might exacerbate a malfunction. While the flight instructor decided to use a 300 ft agl decision check altitude for the autorotations, a power recovery was not initiated. Postaccident examination of the airframe confirmed flight control continuity.

Near the time of the accident and landing to runway 29, the wind originated from 310°, with a wind speed of 11 kts, and gusting to 21 kts. A review of meteorological data found some speed shear in the lowest 2,000 ft agl of about 15 kts above average surface magnitudes near the airport for a period near the accident time.

It is likely that during the practice autorotation, the pilot did not compensate for the gusting wind condition and the speed shear, and the flight instructor did not execute a timely remedial action with initiating a power recovery, which resulted in the helicopter impacting terrain.

Text from the NTSB. Open the NTSB docket for CEN26LA027 for the full record.