Piper J3C-65 N3453K accident near Fortuna, California

Probable cause

The unexpected engine start during hand propping, which resulted in a serious injury. Contributing to the accident was the lack of communication between the pilot and the individual hand propping the engine.

NTSB analysis

The individual attempting to start the engine by turning the propeller (hand prop) reported that, during the first attempt to start the engine, verbal callouts were used. He further reported that the pilot then told him to pull the propeller through three times. The individual said that he then motioned, without a verbal callout to the pilot, that he would pull the propeller through per the pilot's request. The pilot reported that the individual hand-propping the engine pulled the propeller through a second time before he could secure the airplane by turning off the magnetos. As the individual rotated the propeller and reached to grab the other propeller blade, the engine unexpectedly started, which resulted in the propeller striking the individual in the right arm, causing a fracture.

Text from the NTSB. Open the NTSB docket for WPR11LA487 for the full record.