Incident
The pilot of an Aeronca airplane attempted to hand-prop the engine without securing the aircraft and without anyone at the controls. An individual was holding the tail to prevent movement. When the engine started, the Aeronca accelerated forward, breaking free from the pilot and the tail-holder. It then struck another aircraft, a Boeing PT-17 that was idling in the run-up area waiting to depart as part of a two-aircraft flight.
Aftermath
A bystander who tried to stop the Aeronca was knocked to the ground and struck his head. The Aeronca continued turning right until its right front collided with the right front of the Boeing PT-17. The source does not specify any injuries to the pilot, the tail-holder, or the bystander beyond the head strike, nor does it mention damage to the aircraft.
Sequence of Events
The pilot attempted to start the Aeronca's engine by hand-propping, a method that requires manually spinning the propeller. The aircraft was not tied down or otherwise secured, and no one was sitting in the cockpit to operate the controls. Another person held the tail to try to prevent forward movement. When the engine started, the Aeronca moved forward with sufficient force that both the pilot and the tail-holder could not restrain it. A third person attempted to intervene but was knocked down. The Aeronca then veered right and struck the Boeing PT-17, which was parked in the designated run-up area with its engine running, preparing for departure alongside the Aeronca.