Narrative:

I was landing the aircraft. It started swerving on the runway until it got away from me and ran off the runway and hit some very soft sand. A ground loop resulted and very slowly tipped the aircraft over on its back.

Google
 

Original NASA ASRS Text

Title: LOW TIME GA PLT GND LOOPS AND TIPS OVER.

Narrative: I WAS LNDG THE ACFT. IT STARTED SWERVING ON THE RWY UNTIL IT GOT AWAY FROM ME AND RAN OFF THE RWY AND HIT SOME VERY SOFT SAND. A GND LOOP RESULTED AND VERY SLOWLY TIPPED THE ACFT OVER ON ITS BACK.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.