Incident Overview
A flight instructor, seated in the right seat, was demonstrating a short-field landing technique to the aircraft owner. As the aircraft touched down, it encountered a dust devil, also referred to as a whirlwind. The rotational forces imparted by the whirlwind made the aircraft difficult to control at its low forward speed.
Pilot Actions
The instructor pilot elected not to execute a go-around. Despite applying both rudder input and differential braking, the pilot was unable to keep the aircraft from departing the side of the runway.
Post-Departure Events
After leaving the runway, the aircraft entered soft, sandy terrain, which caused it to nose over onto its back.