Aeronca 7AC N83032 accident near Ankeny, Iowa

Probable cause

The pilot's improper starting procedure, which allowed the airplane to move forward over the wheel chocks and impact him and a hangar when he subsequently hand propped the engine.

NTSB analysis

The pilot reported that he attempted to hand prop the engine numerous times without success. He returned to the cockpit and turned the magneto switch to the "off" position and advanced the throttle to between 1/2 and 3/4 travel. He then exited the cockpit and turned the propeller backward five to six "blades" to clear the cylinders. The pilot again returned to the cockpit and turned the magneto switch back to the "on" position, but he did not retard the throttle back to idle. He attempted to hand prop the engine again, and it started. Due to the engine's throttle setting, the airplane moved forward over the wheel chocks and struck the pilot, which resulted in serious injuries, and then a hangar, which resulted in substantial damage to the firewall and fuselage.

Text from the NTSB. Open the NTSB docket for CEN20CA120 for the full record.