Incident Overview
A certificated flight instructor (CFI) was providing flight instruction for a tailwheel endorsement to a certificated commercial pilot under Title 14, CFR Part 91. During the approach, the CFI reported that he inadvertently allowed the commercial pilot to descend before reaching the intended touchdown point. The CFI stated that his verbal command to initiate a go-around was not followed by the commercial pilot, and he was unable to move the commercial pilot's hand from the throttle in order to add full engine power.
Sequence of Events
As the airplane continued descending, it drifted to the right and struck a Visual Approach Slope Indicator (VASI) light box. The impact resulted in substantial damage to the left wing, left wing lift strut, and fuselage. The CFI noted that there were no preaccident mechanical anomalies with the airplane.
Damage Assessment
The airplane sustained substantial damage to the left wing, left wing lift strut, and fuselage. No other damage was reported.
Pilot Comments
The CFI emphasized that the airplane was functioning normally prior to the accident, and no mechanical issues were identified.