Siai-Marchetti SM N772DW accident near Belgrade, Montana

Probable cause

The pilot receiving instruction's overapplication of rudder during the landing roll and his subsequent failure to maintain directional control, which resulted in a ground loop.

NTSB analysis

The flight instructor in the tailwheel-equipped airplane reported that, while the pilot receiving instruction performed a wheel landing, the touchdown was smooth and normal. The pilot reduced the power to idle, the tailwheel lowered, and the airspeed decelerated to about 30 knots. He added that the airplane turned slightly right and that the pilot corrected with "slightly too much left rudder," followed by "too much right rudder," which led to a ground loop. The instructor attempted to recover with heavy left rudder and decided to perform a go-around. He attempted to add power, but he was unable to advance the power lever, which he believed the pilot was holding firmly. The left wing impacted the runway, and airplane nosed over.

The airplane sustained substantial damage to the left wing.

The instructor reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.

Text from the NTSB. Open the NTSB docket for GAA19CA261 for the full record.