The flight instructor reported that during the instructional flight, the student was making a low pass over the snow-covered runway when they experienced a downdraft that decreased the airspeed and increased the descent rate. The flight instructor reported that he was too relaxed and should have added power at that moment, but didn't. The airplane's wheels made contact with the snow and the airplane nosed over and came to rest inverted.

The airplane sustained substantial damage to the wings.

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