Pilot (me, dangit) takes off with no clear flight plan and much too close to the pits. The airplane gets "redirected" by a small gust, I take evasive action while flying slow and climbing, the plane stalls the left wing and does exactly 1/2 turn of spin into August-hard ground from about 10 feet up.
This is what it used to look like:
This was an airplane that I scratch-built 4 or 5 years ago with exactly one real crash before this one. While the empenage and wing will probably fly again the fuselage will most likely be gracing the trash in a little bit.
The second-most frustrating part is not having an aircraft to fly. The really frustrating part is that I have never been able to spin that airplane intentionally -- I think I'm just too conditioned to avoid a hard stall like that.
Ah well, time to work on the backup airplane...