C140 JUMPS CHOCKS AFTER HAND PROP START AND STRIKES A VEHICLE.

Narrative

I INTENDED TO START THE ENG WITH THE INTENT TO WARM THE OIL PRIOR TO AN OIL CHANGE. THE BATTERY WAS LOW; SO I CHOCKED BOTH WHEELS AND HAND PROPPED THE ENG. UPON FIRING; THE ENG WAS IDLING TOO FAST; SO I WALKED AROUND THE WING TO THE PLT'S DOOR TO RETARD THE THROTTLE. I HAD MY L-HAND ON THE DOOR AND AS I REACHED FOR THE THROTTLE; I FELL AND THE DOOR OF THE AIRPLANE SEPARATED FROM THE AIRPLANE. THE ENG WAS MAKING ENOUGH PWR THAT IT JUMPED THE R CHOCK AND BEGAN CIRCLING TO THE L. I ATTEMPTED TO RE-ENTER THE COCKPIT BUT WAS KNOCKED DOWN AGAIN BY THE WING LIFT STRUT. THE AIRPLANE CONTINUED TO CIRCLE TO THE L AND STRUCK MY TRUCK; WHICH STOPPED THE ENG; ALSO DAMAGING THE R WING AND TAIL ASSEMBLY. REFLECTING UPON THIS INCIDENT; IT IS CLR THAT MY PLANE WAS NOT ADEQUATELY RESTRAINED. ONE CLR SOLUTION WOULD HAVE BEEN TO UTILIZE ANOTHER PERSON TO BE AT THE CTLS DURING HAND PROPPING. ANOTHER IS THAT THE R WHEEL WAS ABLE TO JUMP ITS CHOCK; SO HIGHER CHOCKS WOULD HAVE PREVENTED THE PLANE FROM MOVING.