Small Aircraft
Flight Crew Private
Flight Crew Last 90 Days 3; Flight Crew Total 146; Flight Crew Type 35
Situational Awareness; Training / Qualification
Aircraft Equipment Problem Less Severe; Ground Event / Encounter Loss Of Aircraft Control; Ground Event / Encounter Object
Aircraft Aircraft Damaged
Human Factors; Aircraft
I was planning to go up to practice landings; and do a short cross country. I did a thorough preflight; pulled the plane into startup position settled into cockpit; went through checklist and attempted to start the engine. It would turn to the top of the compression stroke and stop. After shutting down all electrical switches; I got out of the plane to turn the engine over a couple times. I propped countless planes in my youth so I try to always treat the propeller as though the mags are hot. As soon as I heard the mag click I knew I was in trouble. The engine started immediately. As I got out of the way; I tried to figure a way to stop the plane. The left brake has been dragging; so the plane veered left as it accelerated. It crossed the taxiway and headed right for the hangar across from mine. The plane struck at 15-20 mph; punching a hole in the hangar and damaging the prop; cowling and left wing of the aircraft.After everything stopped; I got into the cockpit and saw that the mag switch was in the off position. I reached for the key and it clicked left; having been stopped on top of a detent in the switch. I have not attempted to duplicate it.I later remembered that back when I propped planes at my local airport; one of the cardinal rules was don't touch the prop unless the pilot in the cockpit tells you to or you have the key to the plane in your hand. My forgetting that old rule caused my plane and my ego to suffer badly.
Pilot reported that a sudden engine start after turning the propeller caused the plane to accelerate across a ramp and strike a hangar.