Airplane Entered A Left Descending Turn Until The Left Wing Contacted The Ground

Location: Oshkosh, Wisconsin Accident Number: CEN18CA291
Date & Time: July 23, 2018, 09:50 Local Registration: N1666R
Aircraft: Quad City Challenger Aircraft Damage: Substantial
Defining Event: Loss of control in flight Injuries: 1 None
Flight Conducted Under: Part 91: General aviation - Personal

Analysis: The airplane was landing on the ultralight field when the accident occurred. The pilot stated that she made a wide base to final turn because she was unsure about the placement of the runway. Although the pilot added power, the airplane entered a left descending turn until the left wing contacted the ground near the beginning of the runway's displaced threshold. 

The airplane then spun left and slid rearward on the ground until it contacted a chain-link fence. The pilot reported that there were no mechanical anomalies with the airplane that would have precluded normal operation. The pilot's statement, along with a ground-based video of the accident, revealed that the pilot failed to maintain adequate airspeed and exceeded the airplane's critical angle of attack during the base to final turn, which resulted in an aerodynamic stall.

Probable Cause and Findings: The National Transportation Safety Board determines the probable cause(s) of this accident to be -- The pilot's failure to maintain adequate airspeed during the base to final turn and his exceedance of the airplane's critical angle of attack, which resulted in an aerodynamic stall.

FMI: www.ntsb.gov