well, this happens from time to time with the wife in the cockpit and hand propping the engine. reminds me of this event. https://youtu.be/cn7EN1RlVRw?si=aYDHxiOEwBRwKS4k
https://asn.flightsafety.org/wikibase/548095
During startup on ramp, battery died. Pilot went out to remedy the situation and handcrank while his wife stayed in the acft on the brakes. The acft cranked over at full throttle, but the pilot managed to get back in the acft in an attempt to stop. Acft impacted the terminal building, resulting in broken glass and damage to stone facade. Pilot had was conscious and walking with injuries to the head and leg, wife had no injuries.
