The pilot reported that while conducting banner towing operations in Renton, Washington, after the Cessna 150 passed through the banner pick up gates, he applied full throttle and pitched the nose of the airplane up.
Once the airspeed reached 40 miles per hour, he looked back to ensure that the banner pickup was successful.
When he turned back around, the airspeed had decreased, simultaneously the banner began “pulling,” which led to an increase in drag, and the airplane exceeded its critical angle of attack.
The airplane aerodynamically stalled, descended, and hit the ground left wing first, sustaining substantial damage to both wings and the fuselage.
Probable cause: The pilot’s failure to maintain adequate airspeed, which resulted in the airplane exceeding its critical angle of attack and a subsequent aerodynamic stall/spin.
NTSB Identification: GAA15CA175
This July 2015 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.