The flight instructor of the tailwheel equipped airplane reported that the purpose of the flight was to demonstrate a short field takeoff to an observing student.

During the takeoff roll, about rotation speed, the left wing unexpectedly dropped and impacted the ground. Subsequently the airplane ground looped and sustained substantial damage to both wings and the empennage.

The flight instructor reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.