Primary finding
Probable cause
The flight instructor’s improper flap position during takeoff, which resulted in degraded climb performance and a subsequent impact with a building.
Investigator assessment
Analysis narrative
According to the flight instructor, the airplane struggled to maintain altitude during its initial climb following takeoff. A witness reported that the wing flaps were fully deployed during takeoff. Subsequently, the airplane clipped several trees and then its left landing gear struck a power line that resulted in a descent and impact with a building. The airplane sustained substantial damage to the wings, fuselage, and empennage. The flight instructor stated that there were no preimpact mechanical anomalies or malfunctions with the engine that would have precluded normal operation. Postaccident review of the accident site photographs revealed that the airplane’s flaps were extended rather than fully retracted as specified in the airplane’s Pilot Operating Handbook.