N52013

The certified flight instructor (CFI) reported that during the training flight he initiated a simulated engine power failure. The student pilot trimmed the airplane for a glide speed of 65 knots and maneuvered to a nearby grass runway. During the final approach segment, with twenty-degrees of flaps, the student pilot entered a slip. The CFI reported that shortly thereafter the airplane landed. He reported that during the landing roll the airplane hit a “hole or obstacle” and the airplane bounced. The CFI applied power and aborted the landing. After returning to the departure airport, structural damage and skin deformation was discovered to the aft fuselage. The operator reported damage to longerons and an aft bulkhead. The operator reported no mechanical malfunctions or failures with the airplane.