According to the airplane owner, he had loaned the accident airplane to his brother-in-law, and the airplane had subsequently been returned to the owner. When the airplane was returned, the owner said he discovered that the propeller had damage that was consistent with a propeller strike. During a subsequent damage inspection of the airplane, maintenance personnel discovered substantial damage to the airplane’s fuselage and firewall that was consistent with a hard landing event. The owner then confronted the brother-in-law about the damage, and he confirmed that the damage occurred while he was operating the airplane but provided no further information concerning the accident. The owner reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation. Repeated attempts by the National Transportation Safety Board (NTSB) investigator-in-charge to contact the accident pilot were unsuccessful, and he did not submit the required NTSB Pilot/Operator Aircraft Accident/Incident Report Form 6120.1.